You set up a tank, fill it with fish, and the next thing you know they're all dead. It happens frequently to novice, and even experienced, fish owners. A common cause is a toxic amount of ammonia in the aquarium. This can easily be avoided and, if necessary, treated.
Why Ammonia Builds up in Tanks
Ammonia is a by-product of fish waste. It becomes a problem in aquariums because the fish are producing it in a small, enclosed space. Depending on the size of the aquarium and the number of fish in it, ammonia can reach toxic levels in hours. If the ammonia builds too quickly to control, or is left untreated the fish in the tank will die. Ammonia build-up is an unavoidable result of having fish.
Beneficial bacteria that breaks down ammonia into harmless chemicals will gradually build up in the tank. This process is commonly referred to as "cycling" and can take over a month to complete. There are methods, such as purchasing instant cyclers to add to tanks, that can speed this up. Until the cycling is complete the ammonia levels will continue to rise and fish are at risk. In addition to giving the tank time to cycle, there are other ways to prevent ammonia from reaching toxic levels.
Preventing Toxic Ammonia Levels
- Do not overstock
Cramming more fish than a tank can support will cause ammonia levels to skyrocket. Even properly cycled tanks can have problems regulating ammonia if they are overstocked. A general rule-of-thumb is to have at least one gallon of water for every inch of fish. That means that a two inch long fish should have two gallons of water. Three fish that are each an inch long should have at least three gallons. Keep in mind that this is just a general rule of thumb, many fish stores will recommend the minimum size tank for your fish. Also remember that most fish will flourish with extra space.
- Introduce fish slowly
As tempting as it can be to set up a tank and fill it with fish, the more fish there are the faster the ammonia will be produced. It is best to only add a couple of fish at a time and give the bacteria levels in the tank a week or so to adjust. A single hardy fish can be added early in the cycling process to help it along, but ammonia levels should be monitored, just in case.
- Do not overfeed
Decaying food will add ammonia to the water as well. Be sure to not feed more food than your fish will eat in a few minutes. Things like algae wafers can be left overnight for nocturnal fish, but should be removed the following day. A vacuum to remove old food and waste from the bottom of the tank should be used frequently. Be sure to remove uneaten food often.
Identifying Ammonia Poisoning in Fish
There are several signs that ammonia is reaching toxic levels in aquariums. Frequent testing of water quality, especially in new tanks, can prevent this. Monitor fish behavior and watch for changes. If any of these signs are present in your tank, test the water and start treatment.
- Fish gills are discolored, usually red or purple
- Decreased appetite
- Fish laying at the bottom of the tank
- The body or fins are discolored, usually red streaks
- Fish are staying near the surface and appear to be gasping for air
Treating Ammonia in Fish Tanks
If any of these signs are present, or water tests positive for high ammonia levels, start treatment immediately. Products for reducing ammonia levels can be found in pet stores, but aren't always reliable and can result in a bacteria crash which can make ammonia harder to manage until the colony rebuilds.
A water change between 25 and 50% can help reduce ammonia levels without harming bacteria. Be sure to never change out more than 50% of water at a time! Regular water changes between 15 and 25% can help reduce ammonia build-up as well.
A Healthy Aquarium
In order to prevent high levels of ammonia give a tank time to cycle, introduce fish slowly, and be sure to not put too many fish in one tank. A bit of extra patience and care will lead to fish living longer, happier lives.
Take just a few extra minutes to regularly check ammonia levels and it will save you a lot of trouble in the long run. Some pet stores will even test your water for you if you bring in a sample. And if ammonia does rear it's ugly head, don't panic, just do your best to treat and it.
Katie Ouderkirk - Katie Ouderkirk started working at a barn when she was ten. As the years went on she worked at a number of different barns, two zoos, and ...
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