Welcome to my introductory blog on freshwater fish keeping! I myself am a novice, not an expert, fish keeper. While this site should be a good starting point for anyone new to the hobby of freshwater fish keeping, it should certainly not be your only stop or source of information. The information in this blog is not guaranteed to be comprehensive. Nor is the advice I give necessarily the best to follow. This blog is, however, based on logic, my own experiences and to a large degree the advice of others. Keep in mind when reading this blog or any other that advice you get online is worth exactly what you pay for it, and to always double and triple check any information you receive. With that said, good luck with keeping fish, and I hope you enjoy your new hobby!
Please note that more sections are being added, and this blog is being improved all the time. Thank you.
9/11/20
Introduction
So you decided that you want to keep freshwater fish, or maybe you have tried to keep them in the past without much success. Fish keeping can seem difficult if you do not know where to start, and the advice you receive may seem overwhelming and often contradictory. From experience I know that there is nothing worse in the hobby than to carefully set up what you think is the perfect home for your fish, feed them, watch them swim around and marvel at their antics, then find them all dead or dying one day. When budding hobbyists start out, this is usually the fate of their first, and all too often last, batch of fish. For obvious reasons, people who lose a whole tank of fish within a month of buying them often leave the hobby in disgust. After all, fish are supposed to be very easy to keep. Just add water and food and watch them grow, right? It is not that simple, unfortunately, yet if you follow a few basic guidelines, you can successfully keep fish almost that easily.
Fish are some of the most abused pets in the world. They are horribly neglected, stuffed into tanks too small for anything to live in, or even worse, unfiltered bowls. Goldfish receive the majority of this mistreatment, at the fish’s – and the novice hobbyist’s – expense. Goldfish can live for over 20 years and often grow to over a foot in length. They are so badly abused, however, that even supposedly “expert” pet store owners tell people goldfish only last a year or so, while in the same breath offering to sell them a “goldfish” bowl or 1 gallon tank. Goldfish are extremely messy, and require 20 gallons of water for each fish in a well filtered tank. There will be more goldfish information in another section.
The point is most beginners have large numbers of fish deaths not because fish keeping is a difficult hobby, but rather because they are given bad advice, or no information at all when starting out. Now there is one thing you will have to be able to accept before you decide to invest your time and money in the hobby. You will have fish die on you. It doesn’t matter how careful you are, how much good advice you get and follow; you will have times your fish get sick and die. Sometimes a whole tank of fish will die without you being able to save any. The more you learn and more careful you are, the less the chance of this, but it can happen to anyone. There is something called (tongue-in-cheek) the dead fish club, which you can only be a member of and a true fish keeping expert after you have had a thousand or more fish die on you over the years. If you get so attached to the fish you acquire that you cannot bear to lose any, this is not the hobby for you.
It is actually quite amazing that we can keep fish successfully at all, considering their natural environment. We are taking sensitive animals with hundreds or thousands of gallons of water per fish and sticking them in a few gallons of water that is usually much different chemically than their natural homes. Do not let early failures or the seeming complexity of fish keeping turn you off from the hobby. By simply learning some basic facts about fish and fish keeping you can turn your interest into a very successful lifelong hobby.
Fish are some of the most abused pets in the world. They are horribly neglected, stuffed into tanks too small for anything to live in, or even worse, unfiltered bowls. Goldfish receive the majority of this mistreatment, at the fish’s – and the novice hobbyist’s – expense. Goldfish can live for over 20 years and often grow to over a foot in length. They are so badly abused, however, that even supposedly “expert” pet store owners tell people goldfish only last a year or so, while in the same breath offering to sell them a “goldfish” bowl or 1 gallon tank. Goldfish are extremely messy, and require 20 gallons of water for each fish in a well filtered tank. There will be more goldfish information in another section.
The point is most beginners have large numbers of fish deaths not because fish keeping is a difficult hobby, but rather because they are given bad advice, or no information at all when starting out. Now there is one thing you will have to be able to accept before you decide to invest your time and money in the hobby. You will have fish die on you. It doesn’t matter how careful you are, how much good advice you get and follow; you will have times your fish get sick and die. Sometimes a whole tank of fish will die without you being able to save any. The more you learn and more careful you are, the less the chance of this, but it can happen to anyone. There is something called (tongue-in-cheek) the dead fish club, which you can only be a member of and a true fish keeping expert after you have had a thousand or more fish die on you over the years. If you get so attached to the fish you acquire that you cannot bear to lose any, this is not the hobby for you.
It is actually quite amazing that we can keep fish successfully at all, considering their natural environment. We are taking sensitive animals with hundreds or thousands of gallons of water per fish and sticking them in a few gallons of water that is usually much different chemically than their natural homes. Do not let early failures or the seeming complexity of fish keeping turn you off from the hobby. By simply learning some basic facts about fish and fish keeping you can turn your interest into a very successful lifelong hobby.
Emergency Help section
If you have sick fish, dying fish or a serious problem with your water, this is the section for you. If your fish are in a new tank (less than 3 months since you added your first fish) please see the Nitrogen Cycle section after reading this section. Also, read the euthanasia section if putting your fish out of its misery becomes necessary.
The first thing you should do when you have any concern that your tank is in trouble is a significant water change, of 30-50% of the water. Make sure you treat the new water with Amquel or Prime or some other de-chlorinator that eliminates ammonia from chloramines as well as the chlorine. Save enough water to run tests on your water parameters, and once you change the water, test the nitrite, nitrate, ammonia levels and the pH of the water you removed, NOT the tank water you just added fresh, treated water to. Not only will testing the water AFTER the water change give you diluted results, but dechlorinators have a habit of interfering with the indicators in certain test kits, making your test results inaccurate if you test the water after adding treated tap water to your tank. Clean out the filter, rinsing the filter media in removed water from the tank to ensure the water is being adequately filtered. If you have a hospital/quarantine tank available and empty of fish, isolate any fish that have visible symptoms there, leaving the fish that seem healthy in the permanent tank. To do this, you need to acclimate the fish from your main tank to the hospital tank water in the same way you acclimate new purchases to your home tank. Put them in a bag ½ full of tank water, float in the quarantine tank until the temperature of the water is equilibrated (30 minutes), and then add ½ cup of water from the tank to the bag every 15 minutes for an hour. Like fish store water, you don’t want to transfer diseased water to your hospital tank if you can help it, so try not to let any water from the bag into the hospital tank. If your fish will tolerate salt, such as mollies, guppies, tetras, goldfish, etc. add anywhere from 3-5 teaspoons of salt per 5 gallons of water in both the hospital tank and the main tank the fish were originally in. Make sure when you are done treating your fish, if you want to reduce the salt level, it is best to do so slowly. Fish are much better able to handle a sudden increase in salt level than a sudden decrease. Once the water changes and tests are done, you should contact expert help, such as a trustworthy fish store or good online newsgroup. Just beware of adding medications to your tanks without being sure of the disease your fish have, as often the medicines sold for fish are as harmful to the fish as the diseases themselves. Make sure you keep your fish that were sick in the quarantine tank for 1-2 weeks after they appear to have recovered before re-introducing them to the main tank, both to be sure that they are fully healed so as to avoid sickening the remaining fish, and to allow them time to recover from the stress before exposing them to the stress of transferring from one tank to another.
The first thing you should do when you have any concern that your tank is in trouble is a significant water change, of 30-50% of the water. Make sure you treat the new water with Amquel or Prime or some other de-chlorinator that eliminates ammonia from chloramines as well as the chlorine. Save enough water to run tests on your water parameters, and once you change the water, test the nitrite, nitrate, ammonia levels and the pH of the water you removed, NOT the tank water you just added fresh, treated water to. Not only will testing the water AFTER the water change give you diluted results, but dechlorinators have a habit of interfering with the indicators in certain test kits, making your test results inaccurate if you test the water after adding treated tap water to your tank. Clean out the filter, rinsing the filter media in removed water from the tank to ensure the water is being adequately filtered. If you have a hospital/quarantine tank available and empty of fish, isolate any fish that have visible symptoms there, leaving the fish that seem healthy in the permanent tank. To do this, you need to acclimate the fish from your main tank to the hospital tank water in the same way you acclimate new purchases to your home tank. Put them in a bag ½ full of tank water, float in the quarantine tank until the temperature of the water is equilibrated (30 minutes), and then add ½ cup of water from the tank to the bag every 15 minutes for an hour. Like fish store water, you don’t want to transfer diseased water to your hospital tank if you can help it, so try not to let any water from the bag into the hospital tank. If your fish will tolerate salt, such as mollies, guppies, tetras, goldfish, etc. add anywhere from 3-5 teaspoons of salt per 5 gallons of water in both the hospital tank and the main tank the fish were originally in. Make sure when you are done treating your fish, if you want to reduce the salt level, it is best to do so slowly. Fish are much better able to handle a sudden increase in salt level than a sudden decrease. Once the water changes and tests are done, you should contact expert help, such as a trustworthy fish store or good online newsgroup. Just beware of adding medications to your tanks without being sure of the disease your fish have, as often the medicines sold for fish are as harmful to the fish as the diseases themselves. Make sure you keep your fish that were sick in the quarantine tank for 1-2 weeks after they appear to have recovered before re-introducing them to the main tank, both to be sure that they are fully healed so as to avoid sickening the remaining fish, and to allow them time to recover from the stress before exposing them to the stress of transferring from one tank to another.
Getting Started: Basic equipment
This is a list of basic equipment, some essential, some optional, for successful freshwater fish keeping.
1. Aquarium. This is the most obvious piece of equipment, yet improper selection of an aquarium for the fish you want to keep is one of the leading causes of fish deaths. It may seem counter-intuitive, but the smaller the tank, the more work you will have to do to keep your fish alive. Fish produce a lot of waste, as does any living thing. This waste is, of course, harmful to fish if it becomes concentrated. The solution to pollution is dilution, so the more water you have in your tank the easier it is to keep your fish healthy. Remember that any fish you choose naturally lives in bodies of water with many times more gallons of water per fish than you can hope to provide. Imagine being forced to live in a broom closet with no plumbing that is MAYBE cleaned out every other week, and that is what it is like for a fish to be kept in a bowl or tank of only a gallon or two.
So what size of tank should you get? The largest one you can afford and have room for. If you can afford a 300 gallon tank with all the equipment, and have the room for it, get it. You will find it easier than you can imagine filling it with fish. If you only have enough room/money for a 10 gallon tank, consider saving up for something larger, but you can still keep small healthy tropical fish. Remember that shape can be more important than size when it comes to choosing a tank. The tall “tower” or hexagon tanks look neat, but are not the best choice. They have very little surface area, which hinders gas exchange. Also, fish usually enjoy swimming back and forth, not up and down. A tank less than 2 feet across may have as many gallons of water as one three feet long, but it will not provide enough swimming room. This, like a small tank, increases a fish’s stress Finally, consider all THREE dimensions of the tank when deciding what type of fish you want to keep. A 55 gallon tank may be plenty tall and plenty long for say a 14 inch fish, but what about the distance front to back? The common ones are only 13 inches or so. No matter how many gallons it holds, if a fish can touch its nose and tail to opposite panes of glass in your aquarium at the same time, the tank is too small.
2. Aquarium Stand. You of course need some place to put your aquarium. The best thing for this is a stand built for the aquarium type you have. Water is heavy; it weighs over 8 pounds per gallon, plus the gravel, decorations and equipment, as well as the weight of the glass itself. A 10 gallon tank can easily exceed 100 pounds when fully set up. Suppose you have a 30 gallon tank on a book shelf. You set it up and the book case seems to be holding the 300 pounds without a problem. That is, until you bump the end of the book case and the entire unit folds under the weight. Even though a shelf can support hundreds of pounds of pressure straight up and down, that doesn’t mean the unit is designed to withstand the torsion force caused by a relatively slight lateral pressure. A stand made for that specific amount of weight (or more) is your best choice. Remember that a glass tank stand must support the tank all around the bottom edges, and an acrylic tank needs to be supported along the entire bottom surface.
3. Power filter. For whatever fish you get, yes, you need a power filtration unit. While some fish like less water movement than others, you are usually safe getting a filter rated for at LEAST as many gallons as your tank holds. The three general types of filters are canister filters, under gravel filters and external box-type filters. There are other varieties but these are the three most common general types. Under gravel filters are essentially that, the water is sucked down through a large intake network hidden under your gravel and circulated. Canister filters are generally the most expensive type, but also are some of the best filters available, with more options to customize your filter media than most other systems. External filters consist of an intake tube, a filter-media box on the back of your tank, and a small ramp for filtered water to return to the tank. Any filter will work well with your aquarium as long as it circulates the water and provides the three stages of filtration; mechanical filtration (removing particulate matter from the water by straining it through various things), chemical filtration (activated carbon that removes many potentially harmful chemicals is the most common) and biological filtration (the bacteria colonies that break down the nitrogenous wastes produced by your living fish and organic matter decaying). More information on biological filtration is provided in the nitrogen cycle section.
4. Heater and thermometer. A heater is important not just to keep tropical fish tanks at the correct temperature, but also to keep tropical and goldfish tanks at a steady temperature. Too-warm or too-cold water can stress fish less (within reason) than rapid temperature changes. You NEED a thermometer to monitor water temperature, and you are better off with a heater no matter what fish you keep.
5. Tank canopy (lid) and light. The only fish that won’t jump is a dead fish, and if you don’t have a lid on your tank, fish that do jump will soon be dead fish. You need some sort of canopy to keep your fish in the tank. These can be the type with a built-in light, the nice glass hinged type, or even a piece of scrap screen. I would not recommend anything metal though, as rusting metal can severely degrade your water quality if it gets into your tank. A light is not absolutely necessary if you don’t have live plants in your tank, but having one is more natural for the fish, as it simulates daylight and nighttime. Needless to say, your fish also look much better with the proper lighting.
6. Air pump/air stone. Whether this is required or not depends a lot on what type of fish you have, what type of filter you have and what size/shape of tank. If you have live plants in your tank, they provide more oxygen to your tank water than any bubbler. Even if your filter provides adequate oxygenation, you still may want a bubbler for aesthetic reasons. Some fish also enjoy swimming through the bubbles. The choice of air pump and the choice of air stones/bubbling decorations is up to you, but the more small bubbles produced, the more it oxygenates the water. Note, however, that if you use any type of CO2 injection system to nourish your plants, the aerator will remove the CO2 and render it useless.
7. Gravel Vacuum siphon tube. This is a must if you have any type of substrate such as sand or gravel. Some type of siphon, such as an old length of hose, is necessary even if you have a bear bottom tank. The gravel vacuum sucks the decaying food and fish waste from where it gets trapped in the gravel. This should be done during any partial water change.
8. Bucket for water changes. This is obvious, but what is not as obvious is that the bucket must not be used for anything but changing the water from your fish tank, taking the water out and/or adding new. If the bucket has been used for chemicals such as cleansers or other things that don’t belong in an aquarium, get another bucket or you risk poisoning your fish.
9. Water Dechlorinator. This is necessary for anyone who gets their water from a treated source. If your water comes from an untreated well, you do not need to dechlorinate it, but everyone else should keep some dechlorinator handy. Even if you age your water in a bucket to dechlorinate it for your water changes (this works for chlorine only, NOT chloramines, confirm which your water provider uses), you should have a dechlorinator handy for emergency water changes.
10. Test Kits. Test kits are essential when first setting up your tank and throughout the cycling process. They are also useful to have on hand if you have established tanks and there is a problem. If your fish begin to get sick, the first thing you will be asked by anyone you seek advice from is what your ammonia, nitrite, nitrate, pH etc. levels are. Having your own test kits is more convenient, and in the long run less expensive, than having the fish store always test your water for you.
There are of course dozens of chemicals they make test kits for. So what types of test kits do you need, or will be useful at least? More information is in a later section, but the essential ones are pH (acidity/basicity), nitrite (NO2), nitrate (NO3) and ammonia/ammonium (NH3 and NH4). General hardness, known as calcium hardness, and carbonate hardness (GH and KH respectively) you need to determine before you choose fish, but these levels will remain relatively constant, so you can safely rely on pet store testing if you are not trying to alter these levels. Most of the other test kits do not provide any information that is vital to a beginning aquarist. Chlorine is the only other chemical you need to be concerned with, but if you properly dechlorinate your water you do not need to test for it. One final note, you are usually better off using liquid reagent test kits than the quick “dip stick” kits, as the dip sticks are often more expensive and less accurate (though easier to use) than the liquid reagent kits.
11. Aquarium Salt. Some species of fish, such as cory cats, do not tolerate more than a trace of salt in their water. Others, such as goldfish or livebearers, thrive in a lightly salted tank. Salt is also a very effective treatment, both to prevent and cure diseases like Ich. It is often much less stressful to treat fish with salt than other medications as well. If you use salt, use an aquarium salt that is listed for use in freshwater tanks; do not use a marine aquarium mix as those can contain minerals harmful to your fish. Anywhere from a tiny pinch to a ¼ - ½ teaspoon per gallon can be added, depending on species of fish. To treat wounds and disease, a level of 1 tablespoon per 5 gallons up to one teaspoon per gallon is recommended. Remember that when maintaining a salt level, water added to make up for evaporation should NOT have any salt. Salt does not evaporate, so the only way your tank can lose salt is when you remove water in partial water changes.
12. Glass scrubber/scraper. Snails work just as well or even better to keep your aquarium glass clean, as do some fish, but you may not want either of these. To clean your glass of algae then you need one of the scrubby pads on a long handle to remove unwanted buildup on glass. Remember to never use any cleanser in the tank.
13. Gravel/substrate. Gravel is not essential, but it makes the tank look much better. Depending on whether you want real plants, and what kinds, you may want a lot of gravel or just enough to cover the bottom of the tank. If you are not planning on a planted tank, use just enough gravel to cover the bottom. This makes it much easier to keep the gravel clean during partial water changes. The choice of gravel is mostly a question of personal taste and style, though crushed coral/limestone is best if you want to increase (slowly) your general and carbonate hardness.
14. Decorations. Some fish NEED decorations and caves to hide in. Other fish simply do much better if they have things to swim in/around/under/through. An aquarium should have decorations to make it more interesting for the fish as well as its owner, but what you put in is entirely up to you. Just remember that things like limestone rocks and real driftwood seep chemicals that will change the water chemistry of your tank.
This list is far from comprehensive, but is plenty for a beginning aquarist to get started. Note I did NOT include food here, as you should have your tank and all the necessary beginning equipment before you choose what type of fish you want to keep, and the type of food you buy relies on the type of fish you purchase.
1. Aquarium. This is the most obvious piece of equipment, yet improper selection of an aquarium for the fish you want to keep is one of the leading causes of fish deaths. It may seem counter-intuitive, but the smaller the tank, the more work you will have to do to keep your fish alive. Fish produce a lot of waste, as does any living thing. This waste is, of course, harmful to fish if it becomes concentrated. The solution to pollution is dilution, so the more water you have in your tank the easier it is to keep your fish healthy. Remember that any fish you choose naturally lives in bodies of water with many times more gallons of water per fish than you can hope to provide. Imagine being forced to live in a broom closet with no plumbing that is MAYBE cleaned out every other week, and that is what it is like for a fish to be kept in a bowl or tank of only a gallon or two.
So what size of tank should you get? The largest one you can afford and have room for. If you can afford a 300 gallon tank with all the equipment, and have the room for it, get it. You will find it easier than you can imagine filling it with fish. If you only have enough room/money for a 10 gallon tank, consider saving up for something larger, but you can still keep small healthy tropical fish. Remember that shape can be more important than size when it comes to choosing a tank. The tall “tower” or hexagon tanks look neat, but are not the best choice. They have very little surface area, which hinders gas exchange. Also, fish usually enjoy swimming back and forth, not up and down. A tank less than 2 feet across may have as many gallons of water as one three feet long, but it will not provide enough swimming room. This, like a small tank, increases a fish’s stress Finally, consider all THREE dimensions of the tank when deciding what type of fish you want to keep. A 55 gallon tank may be plenty tall and plenty long for say a 14 inch fish, but what about the distance front to back? The common ones are only 13 inches or so. No matter how many gallons it holds, if a fish can touch its nose and tail to opposite panes of glass in your aquarium at the same time, the tank is too small.
2. Aquarium Stand. You of course need some place to put your aquarium. The best thing for this is a stand built for the aquarium type you have. Water is heavy; it weighs over 8 pounds per gallon, plus the gravel, decorations and equipment, as well as the weight of the glass itself. A 10 gallon tank can easily exceed 100 pounds when fully set up. Suppose you have a 30 gallon tank on a book shelf. You set it up and the book case seems to be holding the 300 pounds without a problem. That is, until you bump the end of the book case and the entire unit folds under the weight. Even though a shelf can support hundreds of pounds of pressure straight up and down, that doesn’t mean the unit is designed to withstand the torsion force caused by a relatively slight lateral pressure. A stand made for that specific amount of weight (or more) is your best choice. Remember that a glass tank stand must support the tank all around the bottom edges, and an acrylic tank needs to be supported along the entire bottom surface.
3. Power filter. For whatever fish you get, yes, you need a power filtration unit. While some fish like less water movement than others, you are usually safe getting a filter rated for at LEAST as many gallons as your tank holds. The three general types of filters are canister filters, under gravel filters and external box-type filters. There are other varieties but these are the three most common general types. Under gravel filters are essentially that, the water is sucked down through a large intake network hidden under your gravel and circulated. Canister filters are generally the most expensive type, but also are some of the best filters available, with more options to customize your filter media than most other systems. External filters consist of an intake tube, a filter-media box on the back of your tank, and a small ramp for filtered water to return to the tank. Any filter will work well with your aquarium as long as it circulates the water and provides the three stages of filtration; mechanical filtration (removing particulate matter from the water by straining it through various things), chemical filtration (activated carbon that removes many potentially harmful chemicals is the most common) and biological filtration (the bacteria colonies that break down the nitrogenous wastes produced by your living fish and organic matter decaying). More information on biological filtration is provided in the nitrogen cycle section.
4. Heater and thermometer. A heater is important not just to keep tropical fish tanks at the correct temperature, but also to keep tropical and goldfish tanks at a steady temperature. Too-warm or too-cold water can stress fish less (within reason) than rapid temperature changes. You NEED a thermometer to monitor water temperature, and you are better off with a heater no matter what fish you keep.
5. Tank canopy (lid) and light. The only fish that won’t jump is a dead fish, and if you don’t have a lid on your tank, fish that do jump will soon be dead fish. You need some sort of canopy to keep your fish in the tank. These can be the type with a built-in light, the nice glass hinged type, or even a piece of scrap screen. I would not recommend anything metal though, as rusting metal can severely degrade your water quality if it gets into your tank. A light is not absolutely necessary if you don’t have live plants in your tank, but having one is more natural for the fish, as it simulates daylight and nighttime. Needless to say, your fish also look much better with the proper lighting.
6. Air pump/air stone. Whether this is required or not depends a lot on what type of fish you have, what type of filter you have and what size/shape of tank. If you have live plants in your tank, they provide more oxygen to your tank water than any bubbler. Even if your filter provides adequate oxygenation, you still may want a bubbler for aesthetic reasons. Some fish also enjoy swimming through the bubbles. The choice of air pump and the choice of air stones/bubbling decorations is up to you, but the more small bubbles produced, the more it oxygenates the water. Note, however, that if you use any type of CO2 injection system to nourish your plants, the aerator will remove the CO2 and render it useless.
7. Gravel Vacuum siphon tube. This is a must if you have any type of substrate such as sand or gravel. Some type of siphon, such as an old length of hose, is necessary even if you have a bear bottom tank. The gravel vacuum sucks the decaying food and fish waste from where it gets trapped in the gravel. This should be done during any partial water change.
8. Bucket for water changes. This is obvious, but what is not as obvious is that the bucket must not be used for anything but changing the water from your fish tank, taking the water out and/or adding new. If the bucket has been used for chemicals such as cleansers or other things that don’t belong in an aquarium, get another bucket or you risk poisoning your fish.
9. Water Dechlorinator. This is necessary for anyone who gets their water from a treated source. If your water comes from an untreated well, you do not need to dechlorinate it, but everyone else should keep some dechlorinator handy. Even if you age your water in a bucket to dechlorinate it for your water changes (this works for chlorine only, NOT chloramines, confirm which your water provider uses), you should have a dechlorinator handy for emergency water changes.
10. Test Kits. Test kits are essential when first setting up your tank and throughout the cycling process. They are also useful to have on hand if you have established tanks and there is a problem. If your fish begin to get sick, the first thing you will be asked by anyone you seek advice from is what your ammonia, nitrite, nitrate, pH etc. levels are. Having your own test kits is more convenient, and in the long run less expensive, than having the fish store always test your water for you.
There are of course dozens of chemicals they make test kits for. So what types of test kits do you need, or will be useful at least? More information is in a later section, but the essential ones are pH (acidity/basicity), nitrite (NO2), nitrate (NO3) and ammonia/ammonium (NH3 and NH4). General hardness, known as calcium hardness, and carbonate hardness (GH and KH respectively) you need to determine before you choose fish, but these levels will remain relatively constant, so you can safely rely on pet store testing if you are not trying to alter these levels. Most of the other test kits do not provide any information that is vital to a beginning aquarist. Chlorine is the only other chemical you need to be concerned with, but if you properly dechlorinate your water you do not need to test for it. One final note, you are usually better off using liquid reagent test kits than the quick “dip stick” kits, as the dip sticks are often more expensive and less accurate (though easier to use) than the liquid reagent kits.
11. Aquarium Salt. Some species of fish, such as cory cats, do not tolerate more than a trace of salt in their water. Others, such as goldfish or livebearers, thrive in a lightly salted tank. Salt is also a very effective treatment, both to prevent and cure diseases like Ich. It is often much less stressful to treat fish with salt than other medications as well. If you use salt, use an aquarium salt that is listed for use in freshwater tanks; do not use a marine aquarium mix as those can contain minerals harmful to your fish. Anywhere from a tiny pinch to a ¼ - ½ teaspoon per gallon can be added, depending on species of fish. To treat wounds and disease, a level of 1 tablespoon per 5 gallons up to one teaspoon per gallon is recommended. Remember that when maintaining a salt level, water added to make up for evaporation should NOT have any salt. Salt does not evaporate, so the only way your tank can lose salt is when you remove water in partial water changes.
12. Glass scrubber/scraper. Snails work just as well or even better to keep your aquarium glass clean, as do some fish, but you may not want either of these. To clean your glass of algae then you need one of the scrubby pads on a long handle to remove unwanted buildup on glass. Remember to never use any cleanser in the tank.
13. Gravel/substrate. Gravel is not essential, but it makes the tank look much better. Depending on whether you want real plants, and what kinds, you may want a lot of gravel or just enough to cover the bottom of the tank. If you are not planning on a planted tank, use just enough gravel to cover the bottom. This makes it much easier to keep the gravel clean during partial water changes. The choice of gravel is mostly a question of personal taste and style, though crushed coral/limestone is best if you want to increase (slowly) your general and carbonate hardness.
14. Decorations. Some fish NEED decorations and caves to hide in. Other fish simply do much better if they have things to swim in/around/under/through. An aquarium should have decorations to make it more interesting for the fish as well as its owner, but what you put in is entirely up to you. Just remember that things like limestone rocks and real driftwood seep chemicals that will change the water chemistry of your tank.
This list is far from comprehensive, but is plenty for a beginning aquarist to get started. Note I did NOT include food here, as you should have your tank and all the necessary beginning equipment before you choose what type of fish you want to keep, and the type of food you buy relies on the type of fish you purchase.
Getting started: Tank setup
Ok, so you thought long and hard about how much money you want to spend on your new hobby, and about where you plan to have your tank. The spot you decided on is out of the way of heavy traffic in your house, not directly under or over any vents, and is never in direct sunlight. You bought your tank, and maybe all the other equipment you think you will need and got it home. Now what?
The first thing you should do is fill the tank with water while it is outside and check for leaks, whether it is new or used. A tank that leaks or even falls apart under the pressure of the water outside makes much less of a mess than one that leaks in your living room. Remember that essentially all that is holding your tank together is glass and glue, or a thin layer of injection molded plastic, and this has to support hundreds or thousands of pounds of water. Another very important safety tip is to NEVER try to move a tank that has more than a thin layer of water on the bottom. A tank is designed to hold the huge mass of water it contains while fully supported on all edges and stationary. If you try to move it while it is full of water, a perfectly constructed tank can split down the seal, or the glass can crack in two from the pressure. Always siphon as much water as possible from the tank before moving it at all.
So, your tank you now know is structurally sound and you have it set up on its stand in your house. The first thing to do is to fill it with water. For a freshwater aquarium, especially for a beginning hobbyist, tap water is the best to use. Fill the tank with water from a garden hose or from the sink using buckets if your tank is not that large. Treat the water with dechlorinator if you get your water from a municipal supplier (anywhere other than an untreated well). Before you add gravel or any decorations, make sure you rinse them off in tap water to remove any contaminates that may be present, and to remove the dust that is often on gravel. Do NOT use soap on anything. Set the tank up with your power filter (make sure you do this before adding gravel if you have an under gravel filter :-) ) and start it running. Set the tank up with the heater, thermometer, air pump and bubbler and anything else you have to put in the tank as far as equipment and decorations go. Your tank should run with just water and decorations and equipment for at least a week for the chemistry to stabilize. After that amount of time, test the KH and GH of your tank water, as it may be different than that of your fresh tap water after running in your tank with items and substrate that may be seeping chemicals into your water. Now, after the water has aged, your tank is ready to be cycled!
The first thing you should do is fill the tank with water while it is outside and check for leaks, whether it is new or used. A tank that leaks or even falls apart under the pressure of the water outside makes much less of a mess than one that leaks in your living room. Remember that essentially all that is holding your tank together is glass and glue, or a thin layer of injection molded plastic, and this has to support hundreds or thousands of pounds of water. Another very important safety tip is to NEVER try to move a tank that has more than a thin layer of water on the bottom. A tank is designed to hold the huge mass of water it contains while fully supported on all edges and stationary. If you try to move it while it is full of water, a perfectly constructed tank can split down the seal, or the glass can crack in two from the pressure. Always siphon as much water as possible from the tank before moving it at all.
So, your tank you now know is structurally sound and you have it set up on its stand in your house. The first thing to do is to fill it with water. For a freshwater aquarium, especially for a beginning hobbyist, tap water is the best to use. Fill the tank with water from a garden hose or from the sink using buckets if your tank is not that large. Treat the water with dechlorinator if you get your water from a municipal supplier (anywhere other than an untreated well). Before you add gravel or any decorations, make sure you rinse them off in tap water to remove any contaminates that may be present, and to remove the dust that is often on gravel. Do NOT use soap on anything. Set the tank up with your power filter (make sure you do this before adding gravel if you have an under gravel filter :-) ) and start it running. Set the tank up with the heater, thermometer, air pump and bubbler and anything else you have to put in the tank as far as equipment and decorations go. Your tank should run with just water and decorations and equipment for at least a week for the chemistry to stabilize. After that amount of time, test the KH and GH of your tank water, as it may be different than that of your fresh tap water after running in your tank with items and substrate that may be seeping chemicals into your water. Now, after the water has aged, your tank is ready to be cycled!
Getting Started: Tank cycling and the Nitrogen Cycle
Improperly cycling your tank is the number one cause of failure for beginning aquarium keepers. Though the cycling of an aquarium is a quite simple process, ignorance of the process is widespread, especially among novices. So what does cycling a tank refer to? The word cycle actually has two meanings in keeping a freshwater aquarium. The first “cycle” that we are talking about is the nitrogen cycle. This is similar to the nitrogen cycle you may have learned about in high school biology, and is in fact a small section of the larger total nitrogen cycle. The second use of the word cycle refers to the process of nurturing and allowing the species of bacteria that convert nitrogenous wastes into less harmful chemicals to grow. A tank is fully cycled when all the necessary bacteria to convert ammonia ultimately into nitrate are living in the tank and keeping the ammonia and nitrite levels undetectable.
(Diagram credit to Ilmari Karonen)
The nitrogen cycle is the process in an aquarium by which extremely toxic nitrogenous wastes are converted into relatively harmless nitrogen compounds. This conversion is carried out by bacteria species that are ubiquitous, or everywhere around us (floating in the air, water, etc.). These bacteria that break down the nitrogenous wastes are what people are referring to when they talk about the biological filter of a tank. The first species is the bacteria that convert ammonia into nitrite, and the second type convert nitrite into nitrate. Sources often cite specific species of bacteria in discussing the nitrogen cycle. The microbiology of a fish aquarium is so complex, involving symbiotic and parasitic relationships between dozens or even hundreds of species of microbes, that it is beyond the scope of this blog. Studying the process in that much detail is also unnecessary to understanding what is happening in a tank and why it is happening, from a hobbyist’s point of view. For that reason, I will refer to the biological processes occurring in as simplistic a fashion as I can while imparting the necessary information.
Fish in an aquarium produce waste. There are many components of this waste, but the important one for our purposes is nitrogenous wastes. These wastes are excreted as ammonia, or are quickly turned into ammonia. Ammonia is extremely toxic to fish. One milligram per Liter (part per million, or ppm) of ammonia in water can be fatal to some fish species. Any amount of ammonia stresses fish, making them more susceptible to diseases. Ammonia levels are the number one cause of fish deaths in new aquariums (and a major cause of death in older aquariums) either directly by reaching deadly levels, or because they weaken a fish’s immune system so they cannot fight off disease. The good news is that these ubiquitous bacteria that I mentioned before need nothing more than a steady source of ammonia in your aquarium and a surface to grow on, preferably in the filter media. The bad news is they can take weeks or even months to establish themselves in sufficient quantities to convert the ammonia into nitrite as quickly as it is produced. Nitrite itself is quite toxic to fish, though less so than ammonia. Nitrite has the formula NO2, or one nitrogen bonded to two oxygen atoms. This means that since the formula for ammonia is NH3 (or NH4+ for the ammonium ion), one nitrogen and three hydrogens, that for every molecule of ammonia neutralized, a molecule of nitrite is created. This one-to-one relationship is constant throughout the nitrogen cycle. Once ammonia is being converted steadily into nitrite, a different species of bacteria can begin to establish colonies in your aquarium. Since this is a completely different species of bacteria, and it relies on the nitrite to grow, it cannot begin to establish itself in your tank until your ammonia consuming bacteria are well established. Like the first species, these new bacteria are slow to grow, meaning it can take several weeks to months for enough nitrifying bacteria to be in your tank to convert nitrite into nitrate as fast as it is produced. Just FYI, the only chemical difference between nitrite and nitrate is that nitrate has three oxygens, while nitrite only has two. Nitrate is much less toxic than nitrite, so levels of 20-40 ppm are acceptable to most fish, though the ideal level of nitrate is as close to 0 as you can reasonably keep it. Live plants can help keep nitrate levels lower, as they take nitrate up as a nutrient, but the main method of keeping your nitrate levels under control is through partial water changes.
So now that you know a bit about the nitrogen cycle and how it occurs, you are ready to begin cycling your tank. The common way to do this is to add a single fish of an inexpensive and hardy variety, feed it and let it produce your ammonia for you. This method often kills the fish. You also do NOT want to use feeder fish of any type to cycle your tank, as they are often ill-kept and can introduce diseases to your tank that will kill the fish you add once your tank is cycled. If you use this method, you need to keep measuring the ammonia and nitrite levels, and change part of the water on your tank if they rise to dangerous levels. Needless to say, if you are constantly removing the chemicals that the bacteria you are trying to establish require to grow, you are going to make cycling take longer, not to mention you are torturing and possibly killing a fish in the process. During the cycling of a tank, you will often have your water turn cloudy. This is normal, as there will be a bacteria explosion. This cloudiness will clear up, so don't do multiple water changes to try to eliminate it. You are just removing beneficial bacteria. If cycling with fish, the only thing you should base your water changes on is the nitrite and ammonia levels.
It is for this reason that many hobbyists suggest a fishless method of cycling your aquarium. There are different methods, some involve hanging a dead shrimp in the tank and letting it decay to produce the ammonia, some have you add actual liquid ammonia solution from a bottle to the tank each day, while my preferred method is the “feeding the tank” method. Very basically, you add some fish food to the tank, and in the process of decaying this food produces ammonia in a steady enough supply to create the necessary bacterial culture. To use this method, buy a small bottle of the cheapest flake fish food you can find. Your tank should be filled with water, dechlorinated and have the heater, filter, etc. running by now. To start this method, simply add a pinch of food, very small if you have a small tank, larger if you have a big tank, twice a day. Keep the heater set in the 70 to 80 degrees F range. Every week or so, test the water for ammonia and nitrites. If you don’t register any ammonia OR nitrites, increase the food you add a bit. If you get a reading of either chemical over 5ppm, cut back on how much food you put in the tank. After a week to a couple months, the ammonia level will be 0, and you will get nitrite readings only. At this point you can stop testing for the ammonia. Keep feeding the tank and testing for nitrite until you stop measuring any of that either. When you no longer measure nitrite, start testing every couple days for all three chemicals. Once you can measure 0 ammonia and 0 nitrite, and only nitrate for a week at least, your tank is cycled. While cycling your tank without fish, you don’t need to do water changes as the tank has nothing that will be harmed by too-high levels of nitrogenous wastes. During the cycling process though, you should rinse out your filter media every week or two. Don’t wash it in chlorinated water, as that will kill off the bacteria you are trying to culture. You can just rinse it out in the tank, as there are no fish you need to keep the water clear for, and the gunk will both produce more ammonia for the bacteria to feed on, and likely contains bacteria that will spread throughout the tank and speed up the colonization process. Once you are done with the cycling process, you will need to clean out the decaying food via a series of partial water changes. The next section will cover the procedure for doing these. These water changes should only be started when you are ready to go out to buy your first fish, since if you remove all the gunk that is producing ammonia, your bacteria will starve and your tank will have to cycle all over again when you add your fish. There will be a ton of decaying food in the gravel of your tank by this time, so when you do your water change, you will stir a ton of gunk up. Suck as much as you can up, but you will need to do several changes before you get it all. Since you don’t have to worry about stressing your fish, you can change up to 75% of the water at a time, and just wait long enough between changes for the gunk to settle. On your last water change, take the media out of the filter one last time and rinse it out in the water you removed. Now you need to go get your fish as quickly as possible. Stocking your aquarium with fish is covered here.
There are methods for speeding up your cycling process. If you have an established tank, move some gravel or filter media from that tank to your new one when you add your first fish. There should be enough bacteria in it so you never get any measurable ammonia or nitrite, but test to make sure. You can also borrow media or gravel from a friend's tank, or even a fish store. I personally would avoid a fish store's gravel or filter media as it may contaminate your tank with diseases. There are a number of products such as Cycle on the market, which are essentiall bottled bacteria that can quickly establish the necessary nirtifying bacteria colonies. People have reported mixed results with these. In theory they are perfect, but in reality they need to be kept in special conditions to keep the bacteria alive, such as refrigerated. If they are mishandled in shipping and storage, or too old, you are basically buying a bottle of dirty water that will do nothing to speed up your cycling process. Whether they are worth the money is up to you though.
Getting Started: Partial water changes
In addition to ignorance of the nitrogen cycle, improper water changes are one of the most common problems with beginning and even long-time hobbyists. Water changes are quite simple, and also quite essential to a healthy aquarium. There are several reasons for this. First, wastes build up even in a fully cycled tank, and water with high levels of nitrate and other wastes needs to be diluted with water containing no nitrate. Second, fish need certain minerals that are provided for them in tap water, and that they can run out of if water is not changed for a long period of time. This is even more important to plants, which require a multitude of micronutriants that are often supplied in tap water. The partial water change is also the time to remove dead and decaying debris and waste from the gravel of your aquarium, which can poison your fish if it builds up too high. Water changes need to be performed every week, or even more often if your tank is overstocked or your tank is cycling with fish in it, but in an established tank properly stocked, changing the water only once a month may be enough. Many beginners when they hear water change don’t notice, or aren’t told, the “partial” part. They think their tank should be routinely cleaned, as in sterilized, so they empty ALL of the water, scrub the decorations and gravel with bleach or even soap, dump all the old filter media and replace that, and fill it up with all new tap water. If you read the nitrogen cycle section of this blog, you realize that this is the worst thing you can do if you want a healthy aquarium. Much in fish keeping seems counter-intuitive to the novice, such as the idea that a bigger tank is easier to maintain and that you want bacteria growing in your tank. The reasons for this should be clear by now though. The more water you change, even if you don’t sterilize your tank, the more stressful for the fish, because even if the source of the water for your tank is the same as always, the water chemistry in a tank is constantly drifting, so to a fish the old water in the tank is quite different from the fresh tap water.
So how do you perform a partial water change? It is very simple. You are changing anywhere from 10-45% of your tank water, depending on many factors such as waste levels, how heavily you stocked your tank, the type of fish you have and water change frequency. You need a bucket -- preferably one with gallon amount graduations on the side -- that has never been used for cleaning chemicals, and a siphon hose with gravel vacuum attachment (see equipment section). Turn off the light and take the light and canopy off of the top of your aquarium. If you have a fully submersible heater that will not be exposed when you take some of the water out of your aquarium, you can leave it on, but make sure you unplug it if it will be exposed below the “fill to” line. A heater exposed to air can overheat and crack. You can leave the filter running, as long as the intake will remain below the water level. Many gravel vacuum siphons have a check valve, allowing you to move the wide end up and down rapidly in the water to start the siphon. If not, simply suck on the end of the tube to start the water flowing. You don't need to suck the water all the way to your mouth for the siphon to work, so don't worry about getting tank water in your mouth; you only have to suck water most of the way through the tube. Even if you swollow some tank water though, it is a little gross but it won't hurt you. Use the gravel vacuum end to suck the junk out of the gravel in your tank, working your way through the tank until all the gravel is vacuumed or you have removed the desired amount of water. If you missed some gravel, simply start vacuuming there on your next water change, and if you still have water to remove when the gravel is clean, you can simply suck the rest of the water from anywhere in the tank. Be careful to not catch any fish in your gravel vacuum tube, as they can be injured if they get caught on the small opening where the water enters the small tube of the siphon. If anything clogs your tube, put your finger over the end of the siphon to stop the flow, or if you have to, blow into the tube to release the pressure.
The perfect time to rinse the filter media out is when you have a bucket of old tank water you intend to dump. You should do this every month to maintain proper water flow through your filter. Never sterilize your filter media as that will kill your biological filter. Simply swish the cartridges through the water, scraping any gunk clogging them off. If you have a sponge, squeeze it in the water multiple times until it looks clear of matter clogging the pores. When the desired amount of water is removed, you can add new, dechlorinated tap water. If you salt your tank, remember that to keep a constant level of salt, you need to add the correct number of teaspoons per gallon you REMOVED, not per gallons that you are adding to the tank. This is because the water that you lose to evaporation is simply water lost; the tank still has all the salt you added since it cannot evaporate. Partial water changes are also the best time to clean algae off of the inside of the glass and off of decorations. Remember that you DO NOT want to remove your fish during water changes. It is much more stressful for them to be taken from their tank to a bucket and back to their tank than to simply work around them. Just be careful not to hit them with anything such as a scrub tool or decorations you are replacing in the tank.
Once the tank is cleaned and re-filled, you can replace the canopy, plug back in anything you turned off and your water change is done!
So how do you perform a partial water change? It is very simple. You are changing anywhere from 10-45% of your tank water, depending on many factors such as waste levels, how heavily you stocked your tank, the type of fish you have and water change frequency. You need a bucket -- preferably one with gallon amount graduations on the side -- that has never been used for cleaning chemicals, and a siphon hose with gravel vacuum attachment (see equipment section). Turn off the light and take the light and canopy off of the top of your aquarium. If you have a fully submersible heater that will not be exposed when you take some of the water out of your aquarium, you can leave it on, but make sure you unplug it if it will be exposed below the “fill to” line. A heater exposed to air can overheat and crack. You can leave the filter running, as long as the intake will remain below the water level. Many gravel vacuum siphons have a check valve, allowing you to move the wide end up and down rapidly in the water to start the siphon. If not, simply suck on the end of the tube to start the water flowing. You don't need to suck the water all the way to your mouth for the siphon to work, so don't worry about getting tank water in your mouth; you only have to suck water most of the way through the tube. Even if you swollow some tank water though, it is a little gross but it won't hurt you. Use the gravel vacuum end to suck the junk out of the gravel in your tank, working your way through the tank until all the gravel is vacuumed or you have removed the desired amount of water. If you missed some gravel, simply start vacuuming there on your next water change, and if you still have water to remove when the gravel is clean, you can simply suck the rest of the water from anywhere in the tank. Be careful to not catch any fish in your gravel vacuum tube, as they can be injured if they get caught on the small opening where the water enters the small tube of the siphon. If anything clogs your tube, put your finger over the end of the siphon to stop the flow, or if you have to, blow into the tube to release the pressure.
The perfect time to rinse the filter media out is when you have a bucket of old tank water you intend to dump. You should do this every month to maintain proper water flow through your filter. Never sterilize your filter media as that will kill your biological filter. Simply swish the cartridges through the water, scraping any gunk clogging them off. If you have a sponge, squeeze it in the water multiple times until it looks clear of matter clogging the pores. When the desired amount of water is removed, you can add new, dechlorinated tap water. If you salt your tank, remember that to keep a constant level of salt, you need to add the correct number of teaspoons per gallon you REMOVED, not per gallons that you are adding to the tank. This is because the water that you lose to evaporation is simply water lost; the tank still has all the salt you added since it cannot evaporate. Partial water changes are also the best time to clean algae off of the inside of the glass and off of decorations. Remember that you DO NOT want to remove your fish during water changes. It is much more stressful for them to be taken from their tank to a bucket and back to their tank than to simply work around them. Just be careful not to hit them with anything such as a scrub tool or decorations you are replacing in the tank.
Once the tank is cleaned and re-filled, you can replace the canopy, plug back in anything you turned off and your water change is done!
Getting Started: Which Fish Should You Get?
A full discussion of the pros and cons of all the types of freshwater fish commonly available for sale is beyond the scope of this blog, so you need to do research on your own to make a truly educated decision about what fish species is best for your aquarium. The Krib is a good starting point with a list of good and bad first fish for the beginning aquarist. In general, you simply have to research what fish thrive in your water quality, in the size tank that you have, and that you can do the necessary work to take care of them. Later sections will deal with the care of particular species of fish, but for now I will simply list some fish to stay away from.
Goldfish: Goldfish are in general a bad first fish, as they require a great deal of room and are quite messy fish. They are also one of the most commonly abused fish in the hobby, often stuffed into tiny tanks with only a couple of gallons of water, no filter and no decorations. You will need a large tank if you choose to keep goldfish, especially since they do not thrive if kept alone. In addition, beginners are often sold cheap “feeder” goldfish, which are notorious for carrying diseases.
Dyed fish, especially Painted Glassfish: These are fish which have been chemically dyed to be made more colorful. This process is harmful to the fish, is temporary, and often stresses the fish to the point where they quickly die of disease.
Piranhas: These fish require a great deal of space, as they not only grow big, but also require schools to remain healthy. Feeding them is another concern, as if you feed them too much, it will foul the water, but if you feed them too little, they will turn on one another and your population will quickly decline.
There are many, many more fish to avoid as a beginner, but these are some of the most abused in the hobby, both by aquarists and by fish dealers. The time waiting for your tank to cycle is the perfect time for you to research what type of fish you are interested in!
Goldfish: Goldfish are in general a bad first fish, as they require a great deal of room and are quite messy fish. They are also one of the most commonly abused fish in the hobby, often stuffed into tiny tanks with only a couple of gallons of water, no filter and no decorations. You will need a large tank if you choose to keep goldfish, especially since they do not thrive if kept alone. In addition, beginners are often sold cheap “feeder” goldfish, which are notorious for carrying diseases.
Dyed fish, especially Painted Glassfish: These are fish which have been chemically dyed to be made more colorful. This process is harmful to the fish, is temporary, and often stresses the fish to the point where they quickly die of disease.
Piranhas: These fish require a great deal of space, as they not only grow big, but also require schools to remain healthy. Feeding them is another concern, as if you feed them too much, it will foul the water, but if you feed them too little, they will turn on one another and your population will quickly decline.
There are many, many more fish to avoid as a beginner, but these are some of the most abused in the hobby, both by aquarists and by fish dealers. The time waiting for your tank to cycle is the perfect time for you to research what type of fish you are interested in!
Getting Started: Adding Fish and Stocking your Tank
So, finally you are ready to add fish to your new aquarium! You bought your fish tank and all the equipment you need, you set it up in your home, you cycled the tank using a fishless method and you cleaned it up to make it ready for your new pets. During that time you researched your water parameters and what fish you can successfully keep in your aquarium. So what is the best method for adding your fish to their new home?
When you buy your fish, the pet store should put them in a bag about ½ full of tank water from the pet store. Without opening the bag, float it in your tank for about a half an hour to let the temperature equilibrate. After that amount of time, carefully open the bag and add a quarter to a half of a cup of water from your tank to the bag. Do NOT put any water from the bag into your tank, as it may have parasites or diseases you don’t want in your tank. If you need to remove any water to make room, pour it (carefully and through a net so as not to lose any fish) down the drain. Close the bag back up again and let it float for another 15 minutes. After 15 minutes replace another quarter to half cup of water from the bag with an equal amount from your tank, and let it float another 15 minutes. At this point, examine the fish in the bag. If any have died, take them back to the pet store and explain what happened. If they all look alright, use your net to get the fish out of the bag and into your tank with as little store water being transferred to the tank as possible. Monitor the fish carefully for the next couple weeks, and don’t feed them for at least half a day. Being introduced to a new tank is very stressful for your fish, so they are not likely to eat, or if they do, to fully digest their food until they have settled in.
When stocking a fish tank, you do not want to add more than a couple fish at a time, though you can get away with more if the fish are small and you have a large tank. Basically you don’t want to overload the biological filter with a ton of waste produced by many fish. Add 2 medium sized fish or up to 4 small fish, and monitor the ammonia and nitrite levels for the next week to make sure your biological filter is handling the new source of ammonia. If the levels remain undetectable for a week, you can safely add another batch of fish.
One of the mistakes most beginners make when setting up an aquarium is overstocking the aquarium. Fish need plenty of room to move around, and many species are territorial. This means that putting many fish into a too-small aquarium will cause stress, which as you know by now increases the risk of disease and death in your fish. The rule you will most often hear is you should have 1 inch of fish per gallon of water. Most people do not follow this, but even if they do, they are not following it correctly. One inch of fish per gallon of water applies to thin fish, not fat ones. Examples of fish this rule works for are guppies, neon tetras, white cloud minnows, etc. For medium bodied fish, like Cory cats, barbs, platys, etc., you need 2 gallons of water per inch of fish. Fat fish are fancy goldfish, piranhas, Oscars and similarly shaped fish, and they require 3 gallons of water per inch of fish. While there is some wiggle room if you have lots of healthy plants or you like doing frequent water changes and keep your filter clear of gunk, this is a rule you should adhere to at least until you learn more about fish keeping.
People also violate the 1 inch per gallon rule (or 2 or 3 inches, depending on the fish) when they go by the current length of their fish, rather than basing the number of fish they buy on the ADULT length. A goldfish may only be 2 inches when you buy it, but it can grow up to 8 inches to a foot in length. This means you can’t put 5 2-inch goldfish in a 30 gallon tank, as they will quickly outgrow the tank. When stocking your tank with any fish, you need to determine what the maximum length of the fish you choose will be, and stock the tank based on that. Overstocking will likely overload your biological filter, and will certainly cause more stress on your fish than keeping the tank stocked at a proper level.
When you buy your fish, the pet store should put them in a bag about ½ full of tank water from the pet store. Without opening the bag, float it in your tank for about a half an hour to let the temperature equilibrate. After that amount of time, carefully open the bag and add a quarter to a half of a cup of water from your tank to the bag. Do NOT put any water from the bag into your tank, as it may have parasites or diseases you don’t want in your tank. If you need to remove any water to make room, pour it (carefully and through a net so as not to lose any fish) down the drain. Close the bag back up again and let it float for another 15 minutes. After 15 minutes replace another quarter to half cup of water from the bag with an equal amount from your tank, and let it float another 15 minutes. At this point, examine the fish in the bag. If any have died, take them back to the pet store and explain what happened. If they all look alright, use your net to get the fish out of the bag and into your tank with as little store water being transferred to the tank as possible. Monitor the fish carefully for the next couple weeks, and don’t feed them for at least half a day. Being introduced to a new tank is very stressful for your fish, so they are not likely to eat, or if they do, to fully digest their food until they have settled in.
When stocking a fish tank, you do not want to add more than a couple fish at a time, though you can get away with more if the fish are small and you have a large tank. Basically you don’t want to overload the biological filter with a ton of waste produced by many fish. Add 2 medium sized fish or up to 4 small fish, and monitor the ammonia and nitrite levels for the next week to make sure your biological filter is handling the new source of ammonia. If the levels remain undetectable for a week, you can safely add another batch of fish.
One of the mistakes most beginners make when setting up an aquarium is overstocking the aquarium. Fish need plenty of room to move around, and many species are territorial. This means that putting many fish into a too-small aquarium will cause stress, which as you know by now increases the risk of disease and death in your fish. The rule you will most often hear is you should have 1 inch of fish per gallon of water. Most people do not follow this, but even if they do, they are not following it correctly. One inch of fish per gallon of water applies to thin fish, not fat ones. Examples of fish this rule works for are guppies, neon tetras, white cloud minnows, etc. For medium bodied fish, like Cory cats, barbs, platys, etc., you need 2 gallons of water per inch of fish. Fat fish are fancy goldfish, piranhas, Oscars and similarly shaped fish, and they require 3 gallons of water per inch of fish. While there is some wiggle room if you have lots of healthy plants or you like doing frequent water changes and keep your filter clear of gunk, this is a rule you should adhere to at least until you learn more about fish keeping.
People also violate the 1 inch per gallon rule (or 2 or 3 inches, depending on the fish) when they go by the current length of their fish, rather than basing the number of fish they buy on the ADULT length. A goldfish may only be 2 inches when you buy it, but it can grow up to 8 inches to a foot in length. This means you can’t put 5 2-inch goldfish in a 30 gallon tank, as they will quickly outgrow the tank. When stocking your tank with any fish, you need to determine what the maximum length of the fish you choose will be, and stock the tank based on that. Overstocking will likely overload your biological filter, and will certainly cause more stress on your fish than keeping the tank stocked at a proper level.
Getting Started: Feeding Your Fish
Overfeeding fish is a significant problem with old and new tanks alike. Most fish cannot effectively self-regulate how much they eat. They can literally eat themselves to death in certain circumstances. In addition to this problem, uneaten food in a fish tank decays, producing nitrogenous waste. This strains a tank’s biological filter, and can even poison your fish if the food is not removed. This makes it very important to not over feed your fish.
Fish have different dietary habits and needs depending on the species of fish you have. Many fish are omnivores, meaning they will eat plant or meat based food. They often will eat almost anything you put in the tank. For the fish that are not omnivores, however, it can be quite harmful to feed them food their bodies are not designed to digest. If you feed an herbivore meat or a carnivore plants, at best they will be unable to effectively digest it and will gain little to no nutrition from the food, and at worst it may poison your fish. For this reason, an important responsibility of a fish owner is to learn the dietary needs of the fish you choose to keep. In addition to feeding your fish the correct food, fish do better if they are provided some variety in what they eat. Always feeding the same flake or pellet food to fish is like eating nothing but rice yourself. A variety in your diet benefits you, and the same is true for your fish. You can, depending on the fish you own, feed flakes and/or pellets most of the time, but once or twice a week throw in some fresh or frozen vegetables, or some water-softened peas if your fish is an herbivore or omnivore, or some krill, blood worms (freeze dried, frozen or fresh) or brine shrimp if your fish is a carnivore or omnivore. This variety will not only give your fish some enjoyment, but can also supplement your fish’s diet with needed nutrients if some trace element or another is absent from their normal food.
In a tank with mixed fish, if some are bottom dwellers and some are top feeders, you need to feed the fish in a manner where all the fish have access to the food. Adding a bunch of food at once so that the top feeders don’t get it all is NOT the way to do this. One thing you could try would be to feed some floating food first, and while the top feeders are munching on that, drop in the sinking food for the bottom feeders. You could also try sinking the flakes (if that is what you use) so they float around in all levels of the tank.
One of the biggest reasons most people overfeed their fish is that they always look hungry. The fish are always bouncing off the glass, waiting for food, nibbling at the water surface every time you approach. They wouldn’t be acting like that if they weren’t starving, right? In reality, even though many fish are constantly begging or browsing for food, they are not in fact starving. Even when overfed, fish will often act like they haven’t eaten in days. In general, fish should be fed once or twice a day only as much as they can eat in under 2 minutes. Even less will do for fish like mollies or goldfish that eat algae and plants in the tank. If you don’t think this is enough, next time you feed your fish start a timer and watch as they eat. Watch how much is actually eaten and how much is sucked up by the filter or sinks to the gravel. See how long it actually takes for the food to be all gone. Remember that whatever you put into the tank either decays and produces nitrogenous wastes, or the fish eat it and in the process of digestion turn it into nitrogenous waste. The more you feed, the more ammonia is produced and the more strained your biological filter will be.
Many people worry about their fish when they go out of town, worrying about how they will feed them. The best thing to do when going away for less than a week is to not worry about feeding them at all. Fish can usually last for at least a week without food, so not feeding them at all is better than worrying about who will feed them, whether they will feed them too much. Deciding not to feed the fish has the added advantage of reducing the production of nitrogenous waste, since if the fish are eating less, they are producing less waste. Since you won’t be around to monitor the water quality or do partial water changes if necessary, this can be invaluable. Conversely, the worst thing you can do would be to feed the fish a bunch right before you leave, or put one of those dissolving “vacation feeders” in your tank. The last thing you want to do when leaving for a period of time is to add something to your tank that could alter your water chemistry. Remember, you won’t be able to do water changes if the ammonia spikes, or the pH crashes.
Automatic feeders are an option if you are still worried about your fish starving or you will be out of town for more than a week. These are set on a timer to release each day a compartment of food that you pre-load with however much flake, pellet, etc. food that you want. I would strongly suggest putting a little less food in these compartments than you normally feed your fish when you are home to avoid possible ammonia spikes. Finally, if you have a friend who can stop by to feed your fish, the best thing to do to make sure they do not overfeed your fish is to use those weekly pill organizers to provide the proper daily amount of food. Just have the pill cases filled with whatever amount and type of food you normally feed your fish, and have your friend just empty the correct day into the tank. Again, I would suggest putting a little less than normal in these compartments. Also, it would be a good idea to make sure your pill organizer has NOT been used in the past for actual pills, as residue left over may poison your fish. If you have used them before for pills, make sure all medicine residues are completely gone before you use it for fish food. When you finally return from vacation, the first thing you do should be to test your water parameters and do a partial water change to clean your neglected tank up if it needs it.
Fish have different dietary habits and needs depending on the species of fish you have. Many fish are omnivores, meaning they will eat plant or meat based food. They often will eat almost anything you put in the tank. For the fish that are not omnivores, however, it can be quite harmful to feed them food their bodies are not designed to digest. If you feed an herbivore meat or a carnivore plants, at best they will be unable to effectively digest it and will gain little to no nutrition from the food, and at worst it may poison your fish. For this reason, an important responsibility of a fish owner is to learn the dietary needs of the fish you choose to keep. In addition to feeding your fish the correct food, fish do better if they are provided some variety in what they eat. Always feeding the same flake or pellet food to fish is like eating nothing but rice yourself. A variety in your diet benefits you, and the same is true for your fish. You can, depending on the fish you own, feed flakes and/or pellets most of the time, but once or twice a week throw in some fresh or frozen vegetables, or some water-softened peas if your fish is an herbivore or omnivore, or some krill, blood worms (freeze dried, frozen or fresh) or brine shrimp if your fish is a carnivore or omnivore. This variety will not only give your fish some enjoyment, but can also supplement your fish’s diet with needed nutrients if some trace element or another is absent from their normal food.
In a tank with mixed fish, if some are bottom dwellers and some are top feeders, you need to feed the fish in a manner where all the fish have access to the food. Adding a bunch of food at once so that the top feeders don’t get it all is NOT the way to do this. One thing you could try would be to feed some floating food first, and while the top feeders are munching on that, drop in the sinking food for the bottom feeders. You could also try sinking the flakes (if that is what you use) so they float around in all levels of the tank.
One of the biggest reasons most people overfeed their fish is that they always look hungry. The fish are always bouncing off the glass, waiting for food, nibbling at the water surface every time you approach. They wouldn’t be acting like that if they weren’t starving, right? In reality, even though many fish are constantly begging or browsing for food, they are not in fact starving. Even when overfed, fish will often act like they haven’t eaten in days. In general, fish should be fed once or twice a day only as much as they can eat in under 2 minutes. Even less will do for fish like mollies or goldfish that eat algae and plants in the tank. If you don’t think this is enough, next time you feed your fish start a timer and watch as they eat. Watch how much is actually eaten and how much is sucked up by the filter or sinks to the gravel. See how long it actually takes for the food to be all gone. Remember that whatever you put into the tank either decays and produces nitrogenous wastes, or the fish eat it and in the process of digestion turn it into nitrogenous waste. The more you feed, the more ammonia is produced and the more strained your biological filter will be.
Many people worry about their fish when they go out of town, worrying about how they will feed them. The best thing to do when going away for less than a week is to not worry about feeding them at all. Fish can usually last for at least a week without food, so not feeding them at all is better than worrying about who will feed them, whether they will feed them too much. Deciding not to feed the fish has the added advantage of reducing the production of nitrogenous waste, since if the fish are eating less, they are producing less waste. Since you won’t be around to monitor the water quality or do partial water changes if necessary, this can be invaluable. Conversely, the worst thing you can do would be to feed the fish a bunch right before you leave, or put one of those dissolving “vacation feeders” in your tank. The last thing you want to do when leaving for a period of time is to add something to your tank that could alter your water chemistry. Remember, you won’t be able to do water changes if the ammonia spikes, or the pH crashes.
Automatic feeders are an option if you are still worried about your fish starving or you will be out of town for more than a week. These are set on a timer to release each day a compartment of food that you pre-load with however much flake, pellet, etc. food that you want. I would strongly suggest putting a little less food in these compartments than you normally feed your fish when you are home to avoid possible ammonia spikes. Finally, if you have a friend who can stop by to feed your fish, the best thing to do to make sure they do not overfeed your fish is to use those weekly pill organizers to provide the proper daily amount of food. Just have the pill cases filled with whatever amount and type of food you normally feed your fish, and have your friend just empty the correct day into the tank. Again, I would suggest putting a little less than normal in these compartments. Also, it would be a good idea to make sure your pill organizer has NOT been used in the past for actual pills, as residue left over may poison your fish. If you have used them before for pills, make sure all medicine residues are completely gone before you use it for fish food. When you finally return from vacation, the first thing you do should be to test your water parameters and do a partial water change to clean your neglected tank up if it needs it.
Quarantine Tank/Hospital Tank
Most hobbyists, even experienced ones, do not keep quarantine tanks available for their fish. Having one, or more, is an excellent idea however if you have a good deal of money invested in your fish. This section will discuss these tanks, their uses, and how to set-up and maintain one.
The hospital tank is usually used as a quarantine tank as well, though if you have a lot of room and a lot of extra money, you may want to buy two separate tanks. The point of a HT/QT is twofold. As a hospital tank (HT) the purpose is to separate sick or possibly sick fish from your general population, giving them a chance to recover in an environment where they do not need to worry about bullying and where they cannot infect your other, healthy fish. For sick fish, this tank allows you to medicate only the fish that are actually sick, and at the same time you don’t have to worry about killing your biological media in your main tank/tanks. This includes the ability to salt your sick fish if you have fish living in the community tank that cannot tolerate salt. As a HT, you should move fish into the tank as soon as you see something that makes you think the fish is sick, and you should keep them in there for at least a week or two after they appear to have recovered.
As a quarantine tank (QT) the purpose of the tank is to provide a temporary home to new acquisitions/purchases so that you can monitor your new fish for a few weeks to make sure they are healthy before introducing them to your community tank. If a fish you just bought is carrying a deadly parasite/virus/fungus/bacteria, the QT prevents you from introducing the disease into your general tank and killing off all of your fish. When new fish are being quarantined, you should keep your fish in the tank for 2 weeks or so, as you not only want to make sure they are not sick, but you want them to fully recover from the stress of being introduced to a new tank before moving them to yet another new tank. In general, an HT/QT is a good idea to have if you have the room and money. If you really like spending money, or have a ton of tanks, you may want to keep separate HT’s and QT’s, so you can treat sick fish while observing new purchases in a completely different tank.
When introducing your fish to the HT/QT, whether they are sick fish you have had for a while or brand new fish, you need to carefully acclimate them to the water in the tank. To do this, follow the same prodecures outlined for adding fish to your tank. First, fill a plastic bag 1/2 full of water from the tank the fish is being taken from, and add the fish to the bag (the fish will be given to you like this if you buy it from a store). Float the sealed bag in the HT/QT water for 1/2 hour to equilbrate the temperatures, then add 1/2 cup or so of water from the tank to the bag. Do not get any water from the bag into the HT/QT. Let it float another 15 minutes, then add another 1/2 cup of water, and repeat this for an hour. After an hour, net the fish from the bag and quickly release him into the tank.
Your HT/QT does not need to be large, and since it is a temporary home, you don’t need to follow the 1-3 gallons per inch of fish rule. If you have an Oscar or 1 foot algae eater that gets sick, you don’t need a 36 gallon tank as a HT, a 10 gallon is usually enough for your purposes. The tank should be at least 10 gallons however, unless you don’t have any fish larger than guppies and small tetras. The tank should have the bare minimum in equipment, meaning a power filter, a heater, thermometer and probably a light. The light is not essential, but it is very valuable to observing your fish, especially if you are trying to spot or monitor signs of external disease. The power filter is essential, as you need filtration to keep the water safe, which is even more important than normal to fish trying to recover from an illness. You need a thermometer and heater because many diseases can be treated by increasing the temperature of the water, and even if your fish’s disease cannot be treated this way, steady temperature is essential to reducing stress. You do not want gravel in your HT/QT as that would simply provide a substrate for bacteria/parasites to live, and it interferes with your ability to clean the tank. Decorations may be necessary for fish to hide and feel safe, but they should be non-porous decorations, made of resin is probably best, that can be disinfected easily when you are done using the tank. Do not use live plants, as you would have to kill them after each use of your tank, or you risk spreading disease from one batch of fish to another.
After use, whether as a QT for new fish or a HT for sick fish, after the fish are fully recovered and moved back to their homes/into their new home, you need to disinfectant the tank. This is the exception to the rule that an aquarium should never be sterilized. A QT/HT is the only tank that should be routinely after use. The reason for this is obvious; you just had fish that either were definitely carrying some harmful parasite or disease, or may have been carrying some harmful parasite or disease. Just because the fish recovered or didn’t get sick doesn’t mean the disease is dead and gone, only that the fish was able to fight it off. If you don’t sterilize your QT/HT, you risk infecting any new fish you add to this tank. To sterilize the QT/HT, empty all the water, remove the filter media from the filter and remove any other decorations/equipment. Add a dilute bleach solution, maybe 1 ounce plain Clorox bleach per cup of water (do NOT use Clorox with detergent, just use the regular old-fashioned bleach) and scrub the inside of the tank completely. Do NOT use soap on anything. Wash the inside of the filter in the same manner, as well as the heater, thermometer and any decorations in the tank. Throw away the filter media, as even if you succeed in sterilizing it, it is not worth the risk of having bleach remain in the filter with the potential to poison your fish. Make sure you rinse everything very well in warm or hot water (be careful not to ruin electrical equipment). Let everything air dry at least a couple days after being completely rinsed. At this point it is best to set up your tank with all the equipment and with water so the water is aged and steady when you next need the QT/HT.
Biological filtration poses a unique problem for a QT/HT. You need to sterilize the filter after each use, so you cannot keep a steady biological filter ready for use. You also don’t want ammonia or nitrite spikes in a tank if you are isolating fish for observation or treatment. In my opinion, the best way to have at least some biological filtration available for the QT/HT is to set the filter for that tank up (after it is sterilized as described above) on your most heavily stocked tank, and run it there along with that tank’s normal filtration. This allows bacteria to establish themselves in the filter and be ready for when you need the QT/HT.
The advantages to a QT/HT are numerous, but few hobbyists take advantage of them. I would say that it is pointless to have a QT if you have nothing more than a few guppies/tetras/white cloud minnows/goldfish, but if you have a large number of fish, especially if you have sensitive and/or expensive fish, a QT is a must when adding new fish to your community.
The hospital tank is usually used as a quarantine tank as well, though if you have a lot of room and a lot of extra money, you may want to buy two separate tanks. The point of a HT/QT is twofold. As a hospital tank (HT) the purpose is to separate sick or possibly sick fish from your general population, giving them a chance to recover in an environment where they do not need to worry about bullying and where they cannot infect your other, healthy fish. For sick fish, this tank allows you to medicate only the fish that are actually sick, and at the same time you don’t have to worry about killing your biological media in your main tank/tanks. This includes the ability to salt your sick fish if you have fish living in the community tank that cannot tolerate salt. As a HT, you should move fish into the tank as soon as you see something that makes you think the fish is sick, and you should keep them in there for at least a week or two after they appear to have recovered.
As a quarantine tank (QT) the purpose of the tank is to provide a temporary home to new acquisitions/purchases so that you can monitor your new fish for a few weeks to make sure they are healthy before introducing them to your community tank. If a fish you just bought is carrying a deadly parasite/virus/fungus/bacteria, the QT prevents you from introducing the disease into your general tank and killing off all of your fish. When new fish are being quarantined, you should keep your fish in the tank for 2 weeks or so, as you not only want to make sure they are not sick, but you want them to fully recover from the stress of being introduced to a new tank before moving them to yet another new tank. In general, an HT/QT is a good idea to have if you have the room and money. If you really like spending money, or have a ton of tanks, you may want to keep separate HT’s and QT’s, so you can treat sick fish while observing new purchases in a completely different tank.
When introducing your fish to the HT/QT, whether they are sick fish you have had for a while or brand new fish, you need to carefully acclimate them to the water in the tank. To do this, follow the same prodecures outlined for adding fish to your tank. First, fill a plastic bag 1/2 full of water from the tank the fish is being taken from, and add the fish to the bag (the fish will be given to you like this if you buy it from a store). Float the sealed bag in the HT/QT water for 1/2 hour to equilbrate the temperatures, then add 1/2 cup or so of water from the tank to the bag. Do not get any water from the bag into the HT/QT. Let it float another 15 minutes, then add another 1/2 cup of water, and repeat this for an hour. After an hour, net the fish from the bag and quickly release him into the tank.
Your HT/QT does not need to be large, and since it is a temporary home, you don’t need to follow the 1-3 gallons per inch of fish rule. If you have an Oscar or 1 foot algae eater that gets sick, you don’t need a 36 gallon tank as a HT, a 10 gallon is usually enough for your purposes. The tank should be at least 10 gallons however, unless you don’t have any fish larger than guppies and small tetras. The tank should have the bare minimum in equipment, meaning a power filter, a heater, thermometer and probably a light. The light is not essential, but it is very valuable to observing your fish, especially if you are trying to spot or monitor signs of external disease. The power filter is essential, as you need filtration to keep the water safe, which is even more important than normal to fish trying to recover from an illness. You need a thermometer and heater because many diseases can be treated by increasing the temperature of the water, and even if your fish’s disease cannot be treated this way, steady temperature is essential to reducing stress. You do not want gravel in your HT/QT as that would simply provide a substrate for bacteria/parasites to live, and it interferes with your ability to clean the tank. Decorations may be necessary for fish to hide and feel safe, but they should be non-porous decorations, made of resin is probably best, that can be disinfected easily when you are done using the tank. Do not use live plants, as you would have to kill them after each use of your tank, or you risk spreading disease from one batch of fish to another.
After use, whether as a QT for new fish or a HT for sick fish, after the fish are fully recovered and moved back to their homes/into their new home, you need to disinfectant the tank. This is the exception to the rule that an aquarium should never be sterilized. A QT/HT is the only tank that should be routinely after use. The reason for this is obvious; you just had fish that either were definitely carrying some harmful parasite or disease, or may have been carrying some harmful parasite or disease. Just because the fish recovered or didn’t get sick doesn’t mean the disease is dead and gone, only that the fish was able to fight it off. If you don’t sterilize your QT/HT, you risk infecting any new fish you add to this tank. To sterilize the QT/HT, empty all the water, remove the filter media from the filter and remove any other decorations/equipment. Add a dilute bleach solution, maybe 1 ounce plain Clorox bleach per cup of water (do NOT use Clorox with detergent, just use the regular old-fashioned bleach) and scrub the inside of the tank completely. Do NOT use soap on anything. Wash the inside of the filter in the same manner, as well as the heater, thermometer and any decorations in the tank. Throw away the filter media, as even if you succeed in sterilizing it, it is not worth the risk of having bleach remain in the filter with the potential to poison your fish. Make sure you rinse everything very well in warm or hot water (be careful not to ruin electrical equipment). Let everything air dry at least a couple days after being completely rinsed. At this point it is best to set up your tank with all the equipment and with water so the water is aged and steady when you next need the QT/HT.
Biological filtration poses a unique problem for a QT/HT. You need to sterilize the filter after each use, so you cannot keep a steady biological filter ready for use. You also don’t want ammonia or nitrite spikes in a tank if you are isolating fish for observation or treatment. In my opinion, the best way to have at least some biological filtration available for the QT/HT is to set the filter for that tank up (after it is sterilized as described above) on your most heavily stocked tank, and run it there along with that tank’s normal filtration. This allows bacteria to establish themselves in the filter and be ready for when you need the QT/HT.
The advantages to a QT/HT are numerous, but few hobbyists take advantage of them. I would say that it is pointless to have a QT if you have nothing more than a few guppies/tetras/white cloud minnows/goldfish, but if you have a large number of fish, especially if you have sensitive and/or expensive fish, a QT is a must when adding new fish to your community.
Euthanizing a terminally ill fish
There will come a time when your fish get sick, and there will be nothing that you do that helps them. The emergency section won’t be enough, and simple water parameters don’t explain the condition of your fish. They also will eventually succumb to old age if you have them long enough. Often though, they can last for weeks after becoming terminally ill, suffering in the bottom of your tank or floating around, unable to move unless forced to. At this point, it is often best to end the fish’s suffering rather than let it continue to live in agony. There are many possible methods of euthanasia for a fish; some are much better than others. I will cover a few common ones, and discuss the merits of each.
1. Flushing your fish. This is NEVER a good way to euthanize a fish. You should only flush a fish when it is already dead, if then. Flushing a fish does NOT kill it quickly. The fish will be shocked by the temperature and water chemistry difference, but probably not enough to kill it outright. Then it will be burned by the chlorine and other chemicals in the water. It will travel through a pipe, being bumped and scraped constantly, until it lands in a cesspool of human waste, where it will be further burned by chemicals, attacked by parasites, and eventually suffocated to death. Again, if you are looking to kill your fish quickly, this is NOT the way to do it. If you can’t stand actively killing your fish, it is better to let it die on its own in the tank.
2. Smashing the fish’s head. This is an effective way to kill a fish quickly, but is not necessarily that certain or efficient. Sure, if you can be 100% positive that you will completely crush the entire head of the fish with one sure, quick stroke, than it is an effective method of euthanasia. If you miss though, you just maimed the fish, and it will sit there with its body partially crushed waiting for you to finish the job. Also, the longer the fish has to sit out of water waiting for you to kill it, the longer it is slowly suffocating. This method is much better than flushing a live fish, but there are better methods.
3. Swinging the fish to smack its head on a hard surface. This is not recommended. There simply is too much chance that you won’t be able to kill the fish with a single quick blow. The fish could just be momentarily stunned, or just injured, or your grip could slip and it could go flying without having hit its head at all, etc. This is a method to avoid, though it MIGHT be effective to stun the fish long enough to decapitate it if your fish is flopping too much for a direct decapitation.
4. Decapitation. This involves simply holding the fish on a flat surface and cleanly slicing its head off just behind the gills. If you are squeamish about blood, this is not for you as most fish will bleed visibly if their head is cut off. If you can cut the fish’s head in a clean, smooth swift motion, making sure you decapitate it instantly, this method is a good one. If the fish is flopping, or your hand is not steady enough to cleanly and quickly decapitate it, you should use one of the later methods. If you do choose to decapitate the fish, do so by placing the knife tip-down just above the spine, the quickly rocking the blade back, so it slices through the fish quickly, starting with the spine.
5. Freeze the fish. This involves putting the fish in the freezer in a small amount of water, so it (theoretically) slips into a coma and dies peacefully. The problem with this is that the lowering of temperature gradually for tropical fish, and maybe even for goldfish, is as traumatic as being burned by chemicals. It is possible that the fish really does slip into a coma without suffering, but this cannot be proven until fish learn to talk.
6. Ice-bath shocking the fish to death. This involves preparing a container of ice water, as cold as possible, then dumping the fish into the ice water, instantly shocking it to death. This may be effective, I haven’t tried it but is sounds like it would work. However, the fish may have enough time to be hurt by it before it actually dies. Also, the bigger the fish the longer a sudden temperature change takes to effect it, so I would only use this on little fish.
7. Boiling water shocking the fish to death. Like the ice bath, this is dumping the fish suddenly into a pan of boiling water. I find it more likely that this is instant than the cold water, but it also may be more painful if it isn’t instant. The boiling water is likely high enough temperature to instantly kill a fish, at least a small one. Again, I wouldn’t use this on truly massive fish myself.
8. Dropping the fish into the blender. To me this method seems pointless as far as messing up a blender to kill a fish when there are much more efficient ways to do it, but some people like this method. There are a few things you need to remember if you do this. First, to be quick the blender must be on when you drop the fish in, or it will suffer as it drops onto the blades, then gets flung around until the blades accelerate enough to tear it up. Second, the fish needs to be dropped head first to destroy the central nervous system as quickly as possible. Again, this method seems a little pointless to me.
9. Alcohol poisoning. There are two schools of thought to this method. One says to put the fish in a mild alcohol solution, maybe 10% alcohol at most (1 part vodka to 4 parts water) and the fish will become intoxicated, pass out and die. The second is to put the fish in as pure alcohol as possible (95% grain alcohol for example, aka Everclear) and the alcohol will quickly shock and kill it. While either method will effectively kill your fish, the debate is over which is less painful. While the first method sounds good, slowly drifting off to an inebriated sleep the fish will never wake from, this may not be how it works in reality. The fish may be badly burned by the alcohol on its skin and gills before it passes out. This may be a very painful process. However, it may be less painful than pure alcohol, even though the pure alcohol kills more quickly. Either method would work, but there is no way to say which is better for the fish.
10. Fish anesthesia overdose. This involves overdosing a fish with a sedative in its water, which will painlessly put the fish into a coma, then kill it. This method is probably the least traumatic, though it certainly is the most expensive. If you want to spend a lot of money euthanizing your fish, this is the way to go, but I feel it is completely unnecessary.
11. Finally, if you have a fire pit, a very quick way to euthanize your fish would be to dump the fish into the hottest coals of the fire, where it will instantly be seared to death. Just make sure you cleanly put the fish in a very hot part of the fire, and also that you don’t dump any water with the fish on the fire, as that would simply cool the coals down and prolong the death of your fish.
No matter which method you choose, if you avoid flushing your fish while it is still alive, you are doing a terminally ill fish a favor by killing it as quickly and cleanly as possible. While no one wants to kill their fish, it is sometimes necessary, so keep the guidelines above in mind when considering the best option for euthanizing your fish.
1. Flushing your fish. This is NEVER a good way to euthanize a fish. You should only flush a fish when it is already dead, if then. Flushing a fish does NOT kill it quickly. The fish will be shocked by the temperature and water chemistry difference, but probably not enough to kill it outright. Then it will be burned by the chlorine and other chemicals in the water. It will travel through a pipe, being bumped and scraped constantly, until it lands in a cesspool of human waste, where it will be further burned by chemicals, attacked by parasites, and eventually suffocated to death. Again, if you are looking to kill your fish quickly, this is NOT the way to do it. If you can’t stand actively killing your fish, it is better to let it die on its own in the tank.
2. Smashing the fish’s head. This is an effective way to kill a fish quickly, but is not necessarily that certain or efficient. Sure, if you can be 100% positive that you will completely crush the entire head of the fish with one sure, quick stroke, than it is an effective method of euthanasia. If you miss though, you just maimed the fish, and it will sit there with its body partially crushed waiting for you to finish the job. Also, the longer the fish has to sit out of water waiting for you to kill it, the longer it is slowly suffocating. This method is much better than flushing a live fish, but there are better methods.
3. Swinging the fish to smack its head on a hard surface. This is not recommended. There simply is too much chance that you won’t be able to kill the fish with a single quick blow. The fish could just be momentarily stunned, or just injured, or your grip could slip and it could go flying without having hit its head at all, etc. This is a method to avoid, though it MIGHT be effective to stun the fish long enough to decapitate it if your fish is flopping too much for a direct decapitation.
4. Decapitation. This involves simply holding the fish on a flat surface and cleanly slicing its head off just behind the gills. If you are squeamish about blood, this is not for you as most fish will bleed visibly if their head is cut off. If you can cut the fish’s head in a clean, smooth swift motion, making sure you decapitate it instantly, this method is a good one. If the fish is flopping, or your hand is not steady enough to cleanly and quickly decapitate it, you should use one of the later methods. If you do choose to decapitate the fish, do so by placing the knife tip-down just above the spine, the quickly rocking the blade back, so it slices through the fish quickly, starting with the spine.
5. Freeze the fish. This involves putting the fish in the freezer in a small amount of water, so it (theoretically) slips into a coma and dies peacefully. The problem with this is that the lowering of temperature gradually for tropical fish, and maybe even for goldfish, is as traumatic as being burned by chemicals. It is possible that the fish really does slip into a coma without suffering, but this cannot be proven until fish learn to talk.
6. Ice-bath shocking the fish to death. This involves preparing a container of ice water, as cold as possible, then dumping the fish into the ice water, instantly shocking it to death. This may be effective, I haven’t tried it but is sounds like it would work. However, the fish may have enough time to be hurt by it before it actually dies. Also, the bigger the fish the longer a sudden temperature change takes to effect it, so I would only use this on little fish.
7. Boiling water shocking the fish to death. Like the ice bath, this is dumping the fish suddenly into a pan of boiling water. I find it more likely that this is instant than the cold water, but it also may be more painful if it isn’t instant. The boiling water is likely high enough temperature to instantly kill a fish, at least a small one. Again, I wouldn’t use this on truly massive fish myself.
8. Dropping the fish into the blender. To me this method seems pointless as far as messing up a blender to kill a fish when there are much more efficient ways to do it, but some people like this method. There are a few things you need to remember if you do this. First, to be quick the blender must be on when you drop the fish in, or it will suffer as it drops onto the blades, then gets flung around until the blades accelerate enough to tear it up. Second, the fish needs to be dropped head first to destroy the central nervous system as quickly as possible. Again, this method seems a little pointless to me.
9. Alcohol poisoning. There are two schools of thought to this method. One says to put the fish in a mild alcohol solution, maybe 10% alcohol at most (1 part vodka to 4 parts water) and the fish will become intoxicated, pass out and die. The second is to put the fish in as pure alcohol as possible (95% grain alcohol for example, aka Everclear) and the alcohol will quickly shock and kill it. While either method will effectively kill your fish, the debate is over which is less painful. While the first method sounds good, slowly drifting off to an inebriated sleep the fish will never wake from, this may not be how it works in reality. The fish may be badly burned by the alcohol on its skin and gills before it passes out. This may be a very painful process. However, it may be less painful than pure alcohol, even though the pure alcohol kills more quickly. Either method would work, but there is no way to say which is better for the fish.
10. Fish anesthesia overdose. This involves overdosing a fish with a sedative in its water, which will painlessly put the fish into a coma, then kill it. This method is probably the least traumatic, though it certainly is the most expensive. If you want to spend a lot of money euthanizing your fish, this is the way to go, but I feel it is completely unnecessary.
11. Finally, if you have a fire pit, a very quick way to euthanize your fish would be to dump the fish into the hottest coals of the fire, where it will instantly be seared to death. Just make sure you cleanly put the fish in a very hot part of the fire, and also that you don’t dump any water with the fish on the fire, as that would simply cool the coals down and prolong the death of your fish.
No matter which method you choose, if you avoid flushing your fish while it is still alive, you are doing a terminally ill fish a favor by killing it as quickly and cleanly as possible. While no one wants to kill their fish, it is sometimes necessary, so keep the guidelines above in mind when considering the best option for euthanizing your fish.
To Snail or not to Snail?
One very popular addition to a fish aquarium is a snail. Snails are also considered horrible pests that destroy the plants you are trying to grow. What is behind the difference in these two opinions? Part of it is personal preference, but mostly it is based on the type of snail. Some snails are large, slow moving, very effective at cleaning the aquarium of algae and leave your live plants alone. Other snails are small, incredibly fast at reproducing (they are born pregnant, as some joke) and will eat almost anything that is green in your tank. If you have the right kind of snail they can be amazing creatures that are fun to watch, but if you have the wrong kind, they can be a nightmare.
First on the list is probably the most hated snail type you can find, the pond snail. These snails have conical, “football” shaped shells, and are usually dark brown. These snails are hermaphrodites, which means each snail has both male and female reproductive organs. So long as you have two, the snails can breed with one another. These snails, in addition to being very quick reproducers, eat most vegetation. This makes them a bane, rather than a boon, to most planted aquariums. Most often they are introduced to aquariums when eggs or live snails are on plants that are purchased for an aquarium. Treating the plants to disinfect/de-snail before adding them to the tank is the best way to avoid a snail epidemic.
Malaysian trumpet snails are a common favorite among aquarium keepers. Like the previous two types, trumpet snails are hermaphroditic and can reproduce explosively. One advantage to trumpet snails is that they don’t just skim over surfaces, they actually burrow in the substrate of your tank. This,
combined with the fact that they are nocturnal, makes them hard to detect. These snails are similar in shape to the pond snails, but significantly longer in relation to their girth. They can grow to about 1.5 inches, so they are not massive snails. These snails prefer dead plant matter to live plants, and spend most of their time burrowing into the gravel looking for food. This characteristic makes them very effective at circulating the gravel and cleaning out gunk, but they can make keeping plants planted in the substrate difficult to keep in place.
The final snail type on the list is the apple snail. Apple snails are not a single species, though often the largest apple snails are the only ones commonly labeled as such, with the smaller species called mystery snails. All apple snails have the unique feature of having water-breathing gills on one side of their body and an air-breathing lung on the other. They have a snorkel-like appendage attached to the lung that allows them to breath air while remaining under the water. Any snail with such a feature is by definition an apple snail. Some of the largest apple snails can devour the plants in an aquarium, but the smaller ones commonly sold as mystery snails are usually harmless to your plants. Another feature of apple snails that is different from the
previously covered species is that they are not hermaphroditic; there are distinct male and female members of the group. This means if you intend to breed your apple snails, you will need to purchase several to make sure you get at least one of each sex. You also need to use caution with keeping apple snails; since they can breathe air, they have a habit of leaving their tanks if any openings in the lid are large enough for them to escape. They especially attempt this when they are looking for a place to lay their eggs, as they do not lay their eggs in water. If the snail exits the tank, he will try to go down to get back to water, but obviously if he is on the other side of the glass when he tries to return, he won’t find water, he will glide along your floor until he gets too dry and closes up. The best thing to do to prevent this is to make sure no opening as large as he is exist in the lid of your tank. These are the largest of the snail types covered here, and are the most interesting in my opinion. Some species can grow to be half a foot across! All are quite round in shape, almost spherical, and are available in a variety of colors.
No matter what snail species you have, if you want to keep them healthy you will need to provide hard water. They grow their shells with calcium and carbonate (GH and KH) so a limestone or crushed coral substrate or filter media is a good thing to have if you want to keep snails. Also, when your snails die you should leave the shells in the aquarium so they can re-dissolve and nourish other snails.
So what do you do if you have snails and don’t want them? If you want to reduce the population of snails, you can place a spinach or lettuce leaf in the tank overnight, and collect the snails that gather on it off in the morning. You can also get a fish that eats snails, such as a clown loach. These won’t completely eliminate the problem, but especially a loach will keep the population very well reduced.
First on the list is probably the most hated snail type you can find, the pond snail. These snails have conical, “football” shaped shells, and are usually dark brown. These snails are hermaphrodites, which means each snail has both male and female reproductive organs. So long as you have two, the snails can breed with one another. These snails, in addition to being very quick reproducers, eat most vegetation. This makes them a bane, rather than a boon, to most planted aquariums. Most often they are introduced to aquariums when eggs or live snails are on plants that are purchased for an aquarium. Treating the plants to disinfect/de-snail before adding them to the tank is the best way to avoid a snail epidemic.
The second very common snail that can be introduced to aquariums by hitching a ride on plants is the ramshorn snail. This snail is often dark brown like pond snails, but may be mottled or striped as well. It is shaped like a flat disk, spiraling in on itself, in the shape of a ram’s horn, and thus the name. These snails are much less harmful to plants than the pond snails, but some species will eat certain live plants. They also are hermaphroditic, and prodigious breeders.
Malaysian trumpet snails are a common favorite among aquarium keepers. Like the previous two types, trumpet snails are hermaphroditic and can reproduce explosively. One advantage to trumpet snails is that they don’t just skim over surfaces, they actually burrow in the substrate of your tank. This,
combined with the fact that they are nocturnal, makes them hard to detect. These snails are similar in shape to the pond snails, but significantly longer in relation to their girth. They can grow to about 1.5 inches, so they are not massive snails. These snails prefer dead plant matter to live plants, and spend most of their time burrowing into the gravel looking for food. This characteristic makes them very effective at circulating the gravel and cleaning out gunk, but they can make keeping plants planted in the substrate difficult to keep in place. 
The final snail type on the list is the apple snail. Apple snails are not a single species, though often the largest apple snails are the only ones commonly labeled as such, with the smaller species called mystery snails. All apple snails have the unique feature of having water-breathing gills on one side of their body and an air-breathing lung on the other. They have a snorkel-like appendage attached to the lung that allows them to breath air while remaining under the water. Any snail with such a feature is by definition an apple snail. Some of the largest apple snails can devour the plants in an aquarium, but the smaller ones commonly sold as mystery snails are usually harmless to your plants. Another feature of apple snails that is different from the
previously covered species is that they are not hermaphroditic; there are distinct male and female members of the group. This means if you intend to breed your apple snails, you will need to purchase several to make sure you get at least one of each sex. You also need to use caution with keeping apple snails; since they can breathe air, they have a habit of leaving their tanks if any openings in the lid are large enough for them to escape. They especially attempt this when they are looking for a place to lay their eggs, as they do not lay their eggs in water. If the snail exits the tank, he will try to go down to get back to water, but obviously if he is on the other side of the glass when he tries to return, he won’t find water, he will glide along your floor until he gets too dry and closes up. The best thing to do to prevent this is to make sure no opening as large as he is exist in the lid of your tank. These are the largest of the snail types covered here, and are the most interesting in my opinion. Some species can grow to be half a foot across! All are quite round in shape, almost spherical, and are available in a variety of colors.No matter what snail species you have, if you want to keep them healthy you will need to provide hard water. They grow their shells with calcium and carbonate (GH and KH) so a limestone or crushed coral substrate or filter media is a good thing to have if you want to keep snails. Also, when your snails die you should leave the shells in the aquarium so they can re-dissolve and nourish other snails.
So what do you do if you have snails and don’t want them? If you want to reduce the population of snails, you can place a spinach or lettuce leaf in the tank overnight, and collect the snails that gather on it off in the morning. You can also get a fish that eats snails, such as a clown loach. These won’t completely eliminate the problem, but especially a loach will keep the population very well reduced.
Water Parameters and Test Kits
Whether your tank setup and fish are brand new or decades old, adequate water quality is essential to your fish’s lives. The only truly consistent way to keep track of your water parameters is, of course, to regularly test them. Test kits were briefly discussed in the basic equipment section of this blog, but will be covered here in more detail. Later in this section I will discuss methods and effectiveness of adjusting water chemistry.
The test kits essential to keeping an aquarium are ammonia, nitrite, nitrate and pH test kits. GH (general, or calcium hardness), KH (carbonate hardness, or alkalinity), chlorine, iron, copper, phosphorus and other test kits can give you useful information, but for most aquarists these are not necessary parameters to monitor. Any test kit can give useful information, but many of these test kits are simply a waste of money for the average hobbyist. You need to make sure that the test kits you have are relatively new. The chemicals that are used in these kits do not remain stable forever, and can break down enough to render your kit useless in less than a year from when you buy it in some cases. You would have to research the reagents used in each kit and their chemical properties to know what kits can last for how long, but a good general rule is to dump any kits you have that are over a year old, or to check your results with a newer test kit you have access to if you think your test kit is losing accuracy.
The type of test kit for each parameter you test is important as well, since not all test kits are created equal. Just because it tests for something and has measurements in, say, parts per million (ppm) does not mean it is really that accurate, or even that it is just testing for that chemical. Dip strip test kits are generally the worst type you can get. The only advantage they have is that they are easy to use. These kits are in general less precise and more expensive than liquid reagent test kits. For example, a kit that tests for ammonia and can perform 130 tests using liquid reagents is precise to 0.25 ppm and can be bought for $6.00, while a 0.5 ppm sensitive dip strip box with 25 single use strips costs $14.00. There are of course varying degrees of quality within liquid reagent test kits as well. The inexpensive test kits are not terribly accurate, but generally tell you what you need to know about your water conditions. They can tell you, for example, whether you have no nitrite, or a little nitrite, or a lot of nitrite, even if they can’t accurately measure 0.25 ppm. Remember, just because a test kit has color gradients for quarters of a part per million does NOT mean it is actually accurate to that sensitivity. The kit may have a margin of error of 1-2 or more ppm. There are also available quite costly test kits that are very accurate, so you know if it reads 1.0 ppm, you have that much in your tank, with a very small margin of error. However, at sometimes over a dollar PER TEST, very few aquarium keepers need tests that accurate or expensive. If you have that kind of money, you should first upgrade all of your equipment such as tank, filters, lighting, heaters and fish before you spend that much money on test kits. To me it seems silly to spend $40 for each test kit for a tank holding $15 in fish.
Ammonia is probably the single most dangerous chemical to your fish in a freshwater fish tank. Chlorine and chloramines are just as toxic, if not more so, but they are never produced in your tank, so if you eliminate them in the water you add to the tank before adding it, you don’t have to worry about them. Ammonia, however, can be added into your tank with fresh water, and it is also produced by any animals and decaying material in your tank. In fact, one huge source of ammonia for many tanks is the tap water itself. If your water supplier uses chloramines and not chlorine, even a dechlorinator that “neutralizes” chloramines can leave behind high levels of ammonia in your water. Most dechlorinators neutralize the chlorine part of the chloramines, yet leave the ammonia intact. This means you may be adding as much as 4 ppm or more ammonia in your freshly treated tap water. To avoid this you need a product such as Prime or Amquel or Amquel + that eliminate ammonia as well as chloramines. As discussed in the cycling section of this blog, ammonia in an established, healthy tank is consumed by bacteria as quickly as it is produced, but can be a serious problem for a cycling tank or if the biological filter fails. This is why ammonia should be one of the first things that you test for if you see any symptoms of disease or problems with your fish. Often, even if ammonia poisoning isn’t the direct cause of your fish’s illness, he has the illness because he was weakened by ammonia in the water. During cycling of course you need to test for ammonia regularly to know when the cycling is progressing to the next stage or is finished, and you need to test for it every couple days if you are using live fish to cycle the tank. Other times to test in a healthy tank are when adding fish, for the next week after a filter failure or power outage, or any time you think waste may be building up in your tank. One final note on ammonia test kits; you should avoid Nessler style test kits, such as Nutrafin’s NH3/NH4 test kit. With Nessler kits you cannot detect anything up to 1ppm of ammonia with any reliability. The indicator simply doesn’t change color enough to tell the difference between 0.6 and 0. These kits are characterized by a gradient of colors from clear to dark orange or amber, with the darker color meaning more ammonia. A better choice is a salicylate test kit, which has a gradient from yellow to green, with yellow being no ammonia and darker green meaning higher levels.
Nitrite is right behind ammonia in threat to your fish, and is appropriately the intermediate compound between ammonia and nitrate in the nitrogen cycle. Nitrite is of course quite toxic, though less so than ammonia. Since there are two entirely separate species of bacteria that convert ammonia ultimately into nitrate, you can conceivably have 0 ammonia, yet dangerous levels of nitrite if your biological filter fails. Any time you have reason to test for ammonia, you should test for nitrite as well. The causes of high nitrite are pretty much the same as for high ammonia, but you don’t need to be as alarmed about the nitrite as the ammonia, since ammonia is significantly more toxic to your fish. Test for nitrite when cycling your tank, when your fish get sick, or when you have an equipment failure, as for ammonia.
Nitrate is the last of the “nitrogen cycle compounds” that you should monitor. Nitrate is much less toxic than either nitrite or ammonia, but can still cause problems in your tank. This can be the case for any tank, as there are no bacteria that convert nitrate into less harmful substances. Plants can help by taking up some of the nitrate as nutrients, but the only effective way to eliminate nitrate from your tank is via water changes. However, depending on your water supply where you live, runoff of fertilizer into the local water supply can mean that nitrate is already present in your tap water. If you start getting high levels of nitrate and water changes do not reduce it, you may want to test your tap water for nitrate to see if it is coming from there. Since nitrate is so much less harmful than nitrite or ammonia, you don’t need to test for it very often, but since it is constantly building up in any tank that has fish in it, you do need to test for it regularly. Every 2 weeks to month is a good idea, depending on stocking level of your tank, and how many live plants you have. One thing to note about nitrate tests is that many convert nitrate into nitrite, then test for nitrite, rather than directly testing for nitrate. This is important if you have nitrite levels in your tank. Since you are not supposed to have any nitrite in your tank unless you are cycling it, this characteristic of nitrate test kits is not a problem, but you need to keep it in mind if you have nitrite in your tank. For example, if during cycling you measure 5 ppm nitrite with your nitrite test kit, and your nitrate test kit says you have 5 ppm nitrate, you may have no nitrate at all in your tank at this point; your nitrate test kit may just be measuring nitrite. Also, remember that hobbyist kits are not the most accurate in the world, so if your nitrite test kit says you have 2 ppm nitrite, and your nitrate kit says you have 5 ppm nitrate, you do not necessarily have 3 ppm nitrate, you still may have no nitrate if the 3 point spread is within the COMBINED margins of error of your test kits. The test kit you have may directly test for nitrate, and not nitrite, so you can’t assume that your readings of nitrate are being altered by nitrite levels in your tank. It is just something to keep in mind.
Acidity/basicity of your tank is measured in terms of pH. The pH of a tank is usually around 7, give or take a single pH point, though sometimes the pH can be as high as 9 or as low as 5. The higher the pH, the more basic the water, and the lower the pH, the more acidic the water. While all fish have certain pH ranges that they can live in, some a larger range than others, all fish are sensitive to dramatic changes in pH. Having a stable pH is more important to the health of your fish than having a certain “correct” pH. For example, you may have a fish that “should” be in a pH range of 6.5-7.5. Your water’s pH is a7.8. It is much better for your fish to live in the water at a steady level of 7.8 than to have the pH continually swinging from 7.8 down to 7.4 and back up the 7.8 over and over again as you try to adjust the pH of your tank. You do need to monitor your pH to make sure it is steady. Buildup of waste, limestone-containing stone or substrate and real driftwood in your tank can all alter the pH of your tank. Sometimes this alteration may be desired, such as adding limestone to increase your water hardness. However, you want your pH to stay as steady as possible, or your fish will become stressed and may die. pH should be tested every couple weeks or more often to make sure it is steady and not drifting on you.
Hardness is another common water parameter to test for, though it does not need to be monitored as regularly as the previously discussed parameters. You do need to know how hard your water is to know what type of fish you can keep, but you don’t really need to carefully monitor it for most fish species. There are two components to hardness of water, General Hardness (GH) which is generally talked about in terms of calcium hardness, and Carbonate Hardness (KH) which is also known as alkalinity (not to be confused with basicity). KH acts as a buffer in a fish aquarium, keeping the pH steady. If you have a problem with frequent pH swings, you may need to increase your KH to help buffer your tank. GH and KH are necessary for snails, as they build their shells out of the calcium and carbonate. Since the hardness of your water is fairly steady though, you do not usually need to worry about regular testing of your GH or KH unless you are trying to alter those values.
Chlorine is really not necessary to test for. The amount of chlorine or chloramines in your water (if you live in the United States) will not exceed 4 ppm by EPA regulations. As long as you use a dechlorinator that eliminates chlorine and chloramines, and use enough to eliminate 4 ppm in whatever water you add to your tank, you don’t need to worry about chlorine being in your tank. If you really want to know how much chlorine your water provider uses, or you want to make sure the bucket of water you left our overnight is really free of chlorine, you can of course buy one of the chlorine test kits, but I don’t personally see any need for one.
Copper test kits can be useful if you are using a copper-based treatment for parasites or illness in your tank, as the copper must be at a certain level to be effective, and if it gets too high it can become fatal. Homes with copper pipes also may have some copper in the water that has sat for any period of time in the copper pipes. If you don’t use copper for treatment of your fish though, there isn’t any real need to test for copper. If you are worried about it being in your pipes, simply run your water for 30 seconds to a minute to clear any copper-containing water out of your pipe before filling your bucket. If you have water quality issues that the common parameters, such as nitrogenous wastes and pH can’t explain, you may want to test for heavy metals like copper.
Iron test kits are similar to, though even less vital than, copper test kits. Municipal water supplies often contain trace iron amounts, though they are usually far below a toxic level to fish. If you have plants, iron is a necessary micronutrient as well. Unfortunately, algae also uses iron as a nutrient, so having iron in your water can speed up algae growth. One problem you should be on the lookout for is that rust from any lights or metallic equipment you have over your aquarium may fall into the water. If this happens, your iron level may grow to toxic levels very quickly. It is best to avoid having anything that can rust over uncovered water. In general though, iron is not a necessary water parameter to test for. As with copper, if you have issues in your tank and your water is free from the normal toxins, you may want to test for heavy metals.
Oxygen test kits are available for freshwater or saltwater aquariums, but in freshwater aquariums it is usually not vital to monitor your oxygen level. If you have healthy plants, or good filtration and/or bubblers in your tank, you don’t need to worry about the oxygen level in your tank. If you are worried, it is easier, and often cheaper to simply add some aquarium plants or a bubbler than to constantly monitor your oxygen level. If your level is too low, you will need to add one of those anyway, so in my opinion an oxygen test kit is pointless for a beginning freshwater aquarist.
Phosphate is the last chemical I will discuss that has test kits sold for it, though there are several others. Phosphate is a chemical that is produced as waste from decaying plant and animal matter, and is also present in a fish’s waste. Phosphate, unlike the nitrogenous wastes or heavy metals, is not likely to become toxic to your fish. Rather, like iron, phosphate greatly speeds up algae growth. Plants use phosphate as a fertilizer, yet in a normal tank there is far too much phosphate being added for the plants to absorb all of it. Water changes can keep your phosphate level under control, but unfortunately, in certain areas runoff of water from farmland can have fertilizer in it, so phosphate, like nitrate, can be added in this way to your tank during water changes. If you have a serious algae problem, you may want to test for phosphate to see if this is a problem, but in a freshwater tank it is not vital to test for phosphate.
Once you know your water parameters, you may be tempted to adjust them, either because the fish you want live in a different set of conditions than you have, or because you think your fish will do better with different conditions. There are many products out there that can adjust your water chemistry; from pH up and down to baking soda, there are tons of chemical supplements to alter your aquarium water. I would suggest you not use any of them. As noted earlier, it is much more harmful for a fish to be in constantly changing water than to adjust a less than “ideal” water quality. pH up and pH down do what they say they do, they push up or down the pH of your tank water, but they are very hard to use so that you keep the pH steady. These do not add the necessary buffering to your water, so while they do in fact push the pH up or down, those pH levels can change every easily. Unless you have experience with altering and maintaining a tank’s water chemistry, or you are willing to kill a lot of fish while you learn how tricky it can be, you should leave the pH where it is. The safest way to push the pH up would probably be to add crushed coral or limestone to your tank’s substrate or filter, or add driftwood to your tank to drive the pH down. This is not usually a good thing, but it is more gradual and safer for your fish than adding chemicals from bottles. Hardness is also increased by the addition of limestone or coral, and can also be increased using calcium carbonate (both KH and GH), calcium chloride (only GH) sodium bicarbonate, which is baking soda (only KH) or other products that are designed to increase a fish tank’s hardness. Again, it is often better for fish to live at “incorrect” hardness than to undergo drastic changes, but using limestone as a substrate is not likely to cause dangerous swings in the levels. For heavily planted tanks you may need to add micronutrients if you want the best possible growth. These can be expensive, and more importantly, it can be very hard to find fertilizer without the three MACROnutrients. Your plants get all the nitrate, potassium and phosphate they need from the fish food and waste from fish; they do not need more from fertilizer, and it can poison your fish. CO2 injection is one very common method of fertilizing your plants, and while it can be expensive to set up an injection system, you can make an effective do it yourself system for just a few dollars. In general though, while it is vital to test your water to maintain the quality your fish need to thrive, it is NOT a good idea to start pouring chemicals into your water.
The test kits essential to keeping an aquarium are ammonia, nitrite, nitrate and pH test kits. GH (general, or calcium hardness), KH (carbonate hardness, or alkalinity), chlorine, iron, copper, phosphorus and other test kits can give you useful information, but for most aquarists these are not necessary parameters to monitor. Any test kit can give useful information, but many of these test kits are simply a waste of money for the average hobbyist. You need to make sure that the test kits you have are relatively new. The chemicals that are used in these kits do not remain stable forever, and can break down enough to render your kit useless in less than a year from when you buy it in some cases. You would have to research the reagents used in each kit and their chemical properties to know what kits can last for how long, but a good general rule is to dump any kits you have that are over a year old, or to check your results with a newer test kit you have access to if you think your test kit is losing accuracy.
The type of test kit for each parameter you test is important as well, since not all test kits are created equal. Just because it tests for something and has measurements in, say, parts per million (ppm) does not mean it is really that accurate, or even that it is just testing for that chemical. Dip strip test kits are generally the worst type you can get. The only advantage they have is that they are easy to use. These kits are in general less precise and more expensive than liquid reagent test kits. For example, a kit that tests for ammonia and can perform 130 tests using liquid reagents is precise to 0.25 ppm and can be bought for $6.00, while a 0.5 ppm sensitive dip strip box with 25 single use strips costs $14.00. There are of course varying degrees of quality within liquid reagent test kits as well. The inexpensive test kits are not terribly accurate, but generally tell you what you need to know about your water conditions. They can tell you, for example, whether you have no nitrite, or a little nitrite, or a lot of nitrite, even if they can’t accurately measure 0.25 ppm. Remember, just because a test kit has color gradients for quarters of a part per million does NOT mean it is actually accurate to that sensitivity. The kit may have a margin of error of 1-2 or more ppm. There are also available quite costly test kits that are very accurate, so you know if it reads 1.0 ppm, you have that much in your tank, with a very small margin of error. However, at sometimes over a dollar PER TEST, very few aquarium keepers need tests that accurate or expensive. If you have that kind of money, you should first upgrade all of your equipment such as tank, filters, lighting, heaters and fish before you spend that much money on test kits. To me it seems silly to spend $40 for each test kit for a tank holding $15 in fish.
Ammonia is probably the single most dangerous chemical to your fish in a freshwater fish tank. Chlorine and chloramines are just as toxic, if not more so, but they are never produced in your tank, so if you eliminate them in the water you add to the tank before adding it, you don’t have to worry about them. Ammonia, however, can be added into your tank with fresh water, and it is also produced by any animals and decaying material in your tank. In fact, one huge source of ammonia for many tanks is the tap water itself. If your water supplier uses chloramines and not chlorine, even a dechlorinator that “neutralizes” chloramines can leave behind high levels of ammonia in your water. Most dechlorinators neutralize the chlorine part of the chloramines, yet leave the ammonia intact. This means you may be adding as much as 4 ppm or more ammonia in your freshly treated tap water. To avoid this you need a product such as Prime or Amquel or Amquel + that eliminate ammonia as well as chloramines. As discussed in the cycling section of this blog, ammonia in an established, healthy tank is consumed by bacteria as quickly as it is produced, but can be a serious problem for a cycling tank or if the biological filter fails. This is why ammonia should be one of the first things that you test for if you see any symptoms of disease or problems with your fish. Often, even if ammonia poisoning isn’t the direct cause of your fish’s illness, he has the illness because he was weakened by ammonia in the water. During cycling of course you need to test for ammonia regularly to know when the cycling is progressing to the next stage or is finished, and you need to test for it every couple days if you are using live fish to cycle the tank. Other times to test in a healthy tank are when adding fish, for the next week after a filter failure or power outage, or any time you think waste may be building up in your tank. One final note on ammonia test kits; you should avoid Nessler style test kits, such as Nutrafin’s NH3/NH4 test kit. With Nessler kits you cannot detect anything up to 1ppm of ammonia with any reliability. The indicator simply doesn’t change color enough to tell the difference between 0.6 and 0. These kits are characterized by a gradient of colors from clear to dark orange or amber, with the darker color meaning more ammonia. A better choice is a salicylate test kit, which has a gradient from yellow to green, with yellow being no ammonia and darker green meaning higher levels.
Nitrite is right behind ammonia in threat to your fish, and is appropriately the intermediate compound between ammonia and nitrate in the nitrogen cycle. Nitrite is of course quite toxic, though less so than ammonia. Since there are two entirely separate species of bacteria that convert ammonia ultimately into nitrate, you can conceivably have 0 ammonia, yet dangerous levels of nitrite if your biological filter fails. Any time you have reason to test for ammonia, you should test for nitrite as well. The causes of high nitrite are pretty much the same as for high ammonia, but you don’t need to be as alarmed about the nitrite as the ammonia, since ammonia is significantly more toxic to your fish. Test for nitrite when cycling your tank, when your fish get sick, or when you have an equipment failure, as for ammonia.
Nitrate is the last of the “nitrogen cycle compounds” that you should monitor. Nitrate is much less toxic than either nitrite or ammonia, but can still cause problems in your tank. This can be the case for any tank, as there are no bacteria that convert nitrate into less harmful substances. Plants can help by taking up some of the nitrate as nutrients, but the only effective way to eliminate nitrate from your tank is via water changes. However, depending on your water supply where you live, runoff of fertilizer into the local water supply can mean that nitrate is already present in your tap water. If you start getting high levels of nitrate and water changes do not reduce it, you may want to test your tap water for nitrate to see if it is coming from there. Since nitrate is so much less harmful than nitrite or ammonia, you don’t need to test for it very often, but since it is constantly building up in any tank that has fish in it, you do need to test for it regularly. Every 2 weeks to month is a good idea, depending on stocking level of your tank, and how many live plants you have. One thing to note about nitrate tests is that many convert nitrate into nitrite, then test for nitrite, rather than directly testing for nitrate. This is important if you have nitrite levels in your tank. Since you are not supposed to have any nitrite in your tank unless you are cycling it, this characteristic of nitrate test kits is not a problem, but you need to keep it in mind if you have nitrite in your tank. For example, if during cycling you measure 5 ppm nitrite with your nitrite test kit, and your nitrate test kit says you have 5 ppm nitrate, you may have no nitrate at all in your tank at this point; your nitrate test kit may just be measuring nitrite. Also, remember that hobbyist kits are not the most accurate in the world, so if your nitrite test kit says you have 2 ppm nitrite, and your nitrate kit says you have 5 ppm nitrate, you do not necessarily have 3 ppm nitrate, you still may have no nitrate if the 3 point spread is within the COMBINED margins of error of your test kits. The test kit you have may directly test for nitrate, and not nitrite, so you can’t assume that your readings of nitrate are being altered by nitrite levels in your tank. It is just something to keep in mind.
Acidity/basicity of your tank is measured in terms of pH. The pH of a tank is usually around 7, give or take a single pH point, though sometimes the pH can be as high as 9 or as low as 5. The higher the pH, the more basic the water, and the lower the pH, the more acidic the water. While all fish have certain pH ranges that they can live in, some a larger range than others, all fish are sensitive to dramatic changes in pH. Having a stable pH is more important to the health of your fish than having a certain “correct” pH. For example, you may have a fish that “should” be in a pH range of 6.5-7.5. Your water’s pH is a7.8. It is much better for your fish to live in the water at a steady level of 7.8 than to have the pH continually swinging from 7.8 down to 7.4 and back up the 7.8 over and over again as you try to adjust the pH of your tank. You do need to monitor your pH to make sure it is steady. Buildup of waste, limestone-containing stone or substrate and real driftwood in your tank can all alter the pH of your tank. Sometimes this alteration may be desired, such as adding limestone to increase your water hardness. However, you want your pH to stay as steady as possible, or your fish will become stressed and may die. pH should be tested every couple weeks or more often to make sure it is steady and not drifting on you.
Hardness is another common water parameter to test for, though it does not need to be monitored as regularly as the previously discussed parameters. You do need to know how hard your water is to know what type of fish you can keep, but you don’t really need to carefully monitor it for most fish species. There are two components to hardness of water, General Hardness (GH) which is generally talked about in terms of calcium hardness, and Carbonate Hardness (KH) which is also known as alkalinity (not to be confused with basicity). KH acts as a buffer in a fish aquarium, keeping the pH steady. If you have a problem with frequent pH swings, you may need to increase your KH to help buffer your tank. GH and KH are necessary for snails, as they build their shells out of the calcium and carbonate. Since the hardness of your water is fairly steady though, you do not usually need to worry about regular testing of your GH or KH unless you are trying to alter those values.
Chlorine is really not necessary to test for. The amount of chlorine or chloramines in your water (if you live in the United States) will not exceed 4 ppm by EPA regulations. As long as you use a dechlorinator that eliminates chlorine and chloramines, and use enough to eliminate 4 ppm in whatever water you add to your tank, you don’t need to worry about chlorine being in your tank. If you really want to know how much chlorine your water provider uses, or you want to make sure the bucket of water you left our overnight is really free of chlorine, you can of course buy one of the chlorine test kits, but I don’t personally see any need for one.
Copper test kits can be useful if you are using a copper-based treatment for parasites or illness in your tank, as the copper must be at a certain level to be effective, and if it gets too high it can become fatal. Homes with copper pipes also may have some copper in the water that has sat for any period of time in the copper pipes. If you don’t use copper for treatment of your fish though, there isn’t any real need to test for copper. If you are worried about it being in your pipes, simply run your water for 30 seconds to a minute to clear any copper-containing water out of your pipe before filling your bucket. If you have water quality issues that the common parameters, such as nitrogenous wastes and pH can’t explain, you may want to test for heavy metals like copper.
Iron test kits are similar to, though even less vital than, copper test kits. Municipal water supplies often contain trace iron amounts, though they are usually far below a toxic level to fish. If you have plants, iron is a necessary micronutrient as well. Unfortunately, algae also uses iron as a nutrient, so having iron in your water can speed up algae growth. One problem you should be on the lookout for is that rust from any lights or metallic equipment you have over your aquarium may fall into the water. If this happens, your iron level may grow to toxic levels very quickly. It is best to avoid having anything that can rust over uncovered water. In general though, iron is not a necessary water parameter to test for. As with copper, if you have issues in your tank and your water is free from the normal toxins, you may want to test for heavy metals.
Oxygen test kits are available for freshwater or saltwater aquariums, but in freshwater aquariums it is usually not vital to monitor your oxygen level. If you have healthy plants, or good filtration and/or bubblers in your tank, you don’t need to worry about the oxygen level in your tank. If you are worried, it is easier, and often cheaper to simply add some aquarium plants or a bubbler than to constantly monitor your oxygen level. If your level is too low, you will need to add one of those anyway, so in my opinion an oxygen test kit is pointless for a beginning freshwater aquarist.
Phosphate is the last chemical I will discuss that has test kits sold for it, though there are several others. Phosphate is a chemical that is produced as waste from decaying plant and animal matter, and is also present in a fish’s waste. Phosphate, unlike the nitrogenous wastes or heavy metals, is not likely to become toxic to your fish. Rather, like iron, phosphate greatly speeds up algae growth. Plants use phosphate as a fertilizer, yet in a normal tank there is far too much phosphate being added for the plants to absorb all of it. Water changes can keep your phosphate level under control, but unfortunately, in certain areas runoff of water from farmland can have fertilizer in it, so phosphate, like nitrate, can be added in this way to your tank during water changes. If you have a serious algae problem, you may want to test for phosphate to see if this is a problem, but in a freshwater tank it is not vital to test for phosphate.
Once you know your water parameters, you may be tempted to adjust them, either because the fish you want live in a different set of conditions than you have, or because you think your fish will do better with different conditions. There are many products out there that can adjust your water chemistry; from pH up and down to baking soda, there are tons of chemical supplements to alter your aquarium water. I would suggest you not use any of them. As noted earlier, it is much more harmful for a fish to be in constantly changing water than to adjust a less than “ideal” water quality. pH up and pH down do what they say they do, they push up or down the pH of your tank water, but they are very hard to use so that you keep the pH steady. These do not add the necessary buffering to your water, so while they do in fact push the pH up or down, those pH levels can change every easily. Unless you have experience with altering and maintaining a tank’s water chemistry, or you are willing to kill a lot of fish while you learn how tricky it can be, you should leave the pH where it is. The safest way to push the pH up would probably be to add crushed coral or limestone to your tank’s substrate or filter, or add driftwood to your tank to drive the pH down. This is not usually a good thing, but it is more gradual and safer for your fish than adding chemicals from bottles. Hardness is also increased by the addition of limestone or coral, and can also be increased using calcium carbonate (both KH and GH), calcium chloride (only GH) sodium bicarbonate, which is baking soda (only KH) or other products that are designed to increase a fish tank’s hardness. Again, it is often better for fish to live at “incorrect” hardness than to undergo drastic changes, but using limestone as a substrate is not likely to cause dangerous swings in the levels. For heavily planted tanks you may need to add micronutrients if you want the best possible growth. These can be expensive, and more importantly, it can be very hard to find fertilizer without the three MACROnutrients. Your plants get all the nitrate, potassium and phosphate they need from the fish food and waste from fish; they do not need more from fertilizer, and it can poison your fish. CO2 injection is one very common method of fertilizing your plants, and while it can be expensive to set up an injection system, you can make an effective do it yourself system for just a few dollars. In general though, while it is vital to test your water to maintain the quality your fish need to thrive, it is NOT a good idea to start pouring chemicals into your water.
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