Pond bio filters use bacteria to purify pond water
ammonia, fish, pond, water, poisoning, food, koi, equilibrium, transforming, nitrification cycle, bio filters, installing, temperature, alkaline, balance.
Summary:
The first pollutant to occur in a pond containing fish is a chemical called ammonia. The pond filter is designed to remove this poison.
This section delves a little more deeply into ammonia, what it is in a pond environment and under what circumstances it is really dangerous.
This sounds crazy a fish eats food to grow but in doing so sows the seeds for its own death by poisoning.
This is achieved in a lake for example by restricting food supplies, limiting fish population and ensuring there is a biological balance that prevents ammonia building up.
To understand what can happen and to therefore prevent dire consequences a basic understanding of ammonia chemistry in water helps.
Ammonium is continuously transforming itself into ammonia and hydrogen ions in the water and vice versa.
Changing the situation by changing pH (means the acidity or how alkaline water is) or temperature for example will disturb the old equilibrium and create a new one.
This is another reason for installing an UV light even in the best koi ponds with excellent biofiltration.
Gerry Preston who writes superb articles on koi keeping in the UK magazine "Nishikigoi International" calculated that between 3 and 4% of the dry food fed to koi becomes ammonia which is secreted by the koi into the pond water.
The solution to this potentially disastrous situation of ammonia poisoning is the installation of a well designed biofilter big enough to cope with the existing fish density and also the future stock density that will arise from the fish growing.
This series of reactions is referred to as the nitrification cycle.