Why is there Ammonia in my Koi Pond?

Ammonia comes from many sources and is very toxic to fish in the aquatic environment. Fish naturally excrete Ammonia.  Ammonia is released from fish’s gill tissue when it breathes. It is also released from the fish’s vent when it urinates and defecates. Additionally, decaying organic debris and uneaten fish food create ammonia. Ammonia will accumulate in the confines of a koi hobbyist’s pond.  Ammonia is extremely toxic, even at low levels to all of the pond inhabitants.

Ammonia can exist in two forms when dissolved in water, the first is the free ammonia and this is very poisonous to fish. The second form is known as ionized ammonia which is not quite as harmful as the free form. Ammonia can have a number of detrimental effects on pond fish such as reddening of the fish’s skin and disrupting the ability to regulate water and salts. It will also damage delicate gill tissue, causing swelling of the tissue which may hinder the absorption of oxygen.

If your koi pond water becomes polluted with ammonia, partial water changes need to be performed immediately to reduce the concentration of the pollutant.

What is a safe Ammonia level for a koi pond?

No ammonia is good ammonia. The ideal ammonia level for your koi pond is 0.00 ppm, parts per million. You should be alarmed if the ammonia level reaches 0.25 ppm in your koi pond as water quality is now deteriorating. At this point your fish will be greatly affected by the presence of ammonia. The fish’s gill filaments cannot function normally; they cannot excrete the ammonia that is accumulating within its body. The ammonia will build up internally resulting in fish death.

What are the symptoms of high Ammonia in koi ponds?

Koi that are suffering in high levels of ammonia will become irritated and will exhibit symptoms such as burns on fins and gills, clamped fins, isolation, or lying on the pond bottom.  You may notice that your koi are secreting excessive slime or mucus, experiencing reddening of the fins and skin, and may be gasping at the pond surface. The consequence of prolonged exposure to elevated ammonia will be damage to fishes slime coat and skin, gill malfunction and damage to the delicate gill tissues; resulting in the ideal condition for bacteria to attack the gill tissues and a perfect environment for parasites to flourish.

How do you remove Ammonia from a koi pond?

Ammonia that is accumulating in your koi pond must be reduced in order to maintain good fish health. With the introduction of beneficial bacteria you can reduce the risk of ammonia damage to your fish. Partial water changes are very helpful in reducing high ammonia levels in koi ponds, although pay close attention to the temperature of water being added. In addition, it is suggested that feedings be reduced to help combat high levels of ammonia.