Ask many koi keepers what level of ammonia there would be in a well managed koi pond and their answer will be: “Zero, of course”. But is that true? I cannot imagine a pond in which it is actually possible to achieve this value.
Koi are ammoniotelic. This is a fancy name for a living creature that eats protein and produces nitrogen as a waste product which is then excreted in the form of ammonia.
OK, it’s no secret that koi excrete ammonia into their pond water, but do you know how much? A guide to the quantity of ammonia that is excreted by an active koi is 33 mg per hour per kilo of body weight. To put that a little more simply, a 1 kilogram koi will excrete almost 800 mg of ammonia into it’s pond each day. This is obviously only an approximation because it is dependent on diet and water temperature etc. but it is a surprising amount nonetheless.