What Is New Tank Syndrome?


What is new tank syndrome?


Many otherwise healthy fish are lost because an overenthusiastic aquarist adds too many fish at one time. This is called “new tank syndrome”. This may have something to do with the misconception that filters remove fish waste. The truth is that, while filters may remove large particles, the biggest part of getting rid of fish waste is up to you and some microscopic helpers.

 Land animals like you and I expend a lot of energy converting the ammonia we produce into less toxic chemicals (urea for you and me). Fish are surrounded by large volumes of water and have no need of expending this energy. Dilution keeps ammonia from reaching toxic levels. But in the closed system of an aquarium, this is not the case.

 Thanks to certain bacteria, the ammonia in an aquarium is converted to less toxic nitrite and then to even less toxic nitrate. Nitrate is then removed by the aquarist with water changes. These bacteria, however, need time to multiply and reach numbers adequate for the amount of ammonia being produced. Adding too many fish at once overwhelms the bacterial population and the levels of ammonia become high enough to kill the fish.

 The rule of thumb is to add no more than one inch of fish per five to ten gallons of water and then wait about six weeks before adding more. (This waiting period can be shortened by adding bacterial supplements.) A more accurate method is to buy a test kit and change the water to keep ammonia and nitrite levels low. Wait until both ammonia and nitrite levels consistently measure zero before adding more fish.

For further information or to schedule an appointment, call Hudson Veterinary Hospital at (330)650-2929.