Ammonia (NH3) is the next deadliest toxin in pond water, right after chlorine. Every time fish digest their food, they emit a waste product known as ammonia through their gill tissue and their kidney. Ammonia may accumulate in ponds when there is too much food, organic particles, and decay of dead fish tissues. When ammonia builds up, it can lead to fish’s skin to redden. It also damages the gills through its direct contact with them. If a fish’ gills are harmed first, the fish are unable to excrete ammonia normally. Also, if the ammonia levels in a pond are excessive, fish simply cannot excrete ammonia through against this harsh environment. In tough situations like these, fish will die.
Eventually, the rate of ammonia level build-up in a new pond will lessen as biological filtration works, but another toxic element will be taking over as this occurs. Ammonia is transformed by the nitrosomonas bacteria into nitrites that are also dangerous to the fish, but less lethal as ammonia. Nitrite levels thus increase as the ammonia levels drop in a new pond.
Take out all fallen branches, leaves, decaying plants or dead fish which often lead to more ammonia development. Also, you can increase more oxygen for the fish pond through the use of aerators.
One technique to help the pond restore is (if possible) to make your pond deeper so the concentration of ammonia in the water is smaller. This can be accomplished by eliminating bottom decaying stuff or removing dirt. Adding an inch or even less of depth can help here.
Koi Clubs USA suggests adding a salt water mixture should help break down ammonia and nitrates. For every 10 gallons of water, add one 1/4 oz. of salt.
Addition of a special chemical can be an alternative solution as well. These liquids can remove ammonia, nitrates and other unwanted substances from a koi pond. Water gets clearer, bad smells go away and the whole pond is more healthy and balanced.
A regular test for ammonia and nitrate ranges is suggested, while this frequency may be lessened if the pond has aged enough and steady readings are by now being taken routinely.
A healthy pond translates to less maintenance and a better garden!