Koi ponds often have a different design to “normal” garden ponds. This is due to the fact that koi regard pond plants as a great supplement to their daily diet and also because their high metabolism leads to heavy soiling. This can be remedied by a bottom drain and a good filter. The gravel is often omitted to prevent the bottom drain from clogging.
Not all Koi fans like marshy areas, where putrefaction processes can take place, germs can reproduce and where the shallow depth heats up the pond in summer. The use of a little technology will reward you with an efficiently running pond, in which the animals are the centre of attention. Keeping grey herons away from koi ponds is an important issue (see Pond dwellers ).
In view of the size koi can grow to, there should be at least 2000-3000 litres available per fish. The Ogata koi farm in Japan provides 256 cubic metres of water for each koi! This is a brief reminder not to overstock your pond, which is one of the main mistakes in koi keeping. The larger water volume also impacts the animals’ health positively because the germ load is lower and the risk of infection decreases.