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How To Treat Fish for Ammonia Burns

Cause, Symptoms & Recommended Treatment


When ammonia in fresh or saltwater reaches a toxic level sufficient enough, the surface areas of a fish's eyes, fins and gills are chemically "burnt", which causes the protective mucus from these surfaces to be removed. This then allows parts of the body to become exposed to deteriorate, which in turn primarily leads to external and/or internal bacterial infections. The occurance of fishes becoming ill from ammonia burns is most commonly associated with the following situations.

  • During Tank Cycling

  • The build-up of ammonia to a toxic level is the first step in the cycling process of a new aquarium.

  • During Transportation

  • Whether purchasing fish from an online supplier or your LFS, if preventive steps are not taken, toxic levels of ammonia in the bag shipping water can be reached in a rather short period of time. This applies just the same for the water in a transport container when packing-up and moving fish as well.

  • During Acclimation Procedures

  • Tied into the situation above, after you have reached your destination the animals in the bags or transport containers need to be acclimated before placing them into their new home. No matter which method you choose to do this, the extended time they are in the water during the process, ammonia will continue or begin to build-up again.

  • During Treatment for Diseases

  • When fish are confined to a container for treatment of a disease or illness, there is no good biological bacteria present to keep ammonia in check, which in turn allows it to build-up. This also applies to treating animals in a QT, because many medications will kill the beneficial bacteria as well.

  • When New Tank Syndrome Occurs

  • When too many fish and/or other animals are too quickly added to even a well seasoned or cycled tank, the problem of the excess bioload overpowers the biological filter's capability to compensate.

Typical Symptoms

The effects of ammonia burns usually do not appear until 2 or 3 days after being exposed. Signs to look for are ragged or frayed fins, cloudy eyes, rapid gilling, and a lack of appetite. Red blotches or streaks may also appear on a fish's body, which is a typical symptom associated with bacterial infections.

Recommended Treatment

Notice of effective treatment can usually be seen in 3 to 5 days. However, treatment should be continued until the fish is eating normally, at which time it can then be returned to the main tank. Here's what to do:

Preventative Measures

With the exception of the tank cycling process and new tank syndrome, the best way to avoid and keep ammonia burn from happening is to add some type of ammonia buffer or destroyer product to the water to neutralize it. AmQuel by Kordon (shop & compare prices) is highly recommended for this purpose.

~Stan & Debbie Hauter

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