The reason you should install an UV light even in the best koi ponds with excellent biofiltration

This is a 250 word (approx) summary of a chapter from my book . Each chapter or main topic has been summarised in this way. For a complete list of summaries see the right hand column

Concepts:

ammonia, fish, pond, water, poisoning, food, koi, equilibrium, transforming, nitrification cycle, biofilter, installing, temperature, alkaline, balance.

Summary:

- The first pollutant to occur in a pond containing fish is a chemical called ammonia.

- 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.