Koi are large ornamental fish imported from Japan. Their brightly coloured patterning and energetic, muscular movements make koi an extremely popular choice for large outdoor ponds.

Koi are descended from the carp of Eastern Asia and Chinese carp farming dates back to about 500 years BC. When China invaded Japan in 1281 they introduced the fish into the rivers and lakes across the islands.

About four centuries later, farmers in Northern Japan began to keep the Magoi (black carp) in small lakes, as a cultivated food source. Because the conditions were sheltered from natural predators – the development of patches of white and bright colour were encouraged in the cross breeding and, by the mid 1800s, the farmers had created the intensely-coloured specimens we know today.

Visitors to aquatics centres often become absolutely enthralled with koi – some developing a keen desire to create their own koi pond.

The installation of a sunken outdoor pond – suitable for koi – needs consideration, planning and, perhaps, professional advice and expertise. In order to maintain a suitable environment for koi, the water needs to be clean and well-oxygenated (a large area - at least four feet deep - with an effective filter system). This means that there has to be adequate provision for water supply and drainage pipes as well as a safe electricity supply for heaters, pumps, water treatment equipment and filter systems.

Care must be taken to feed koi a correctly balanced diet (check with a reputable source). There is helpful and informative literature available and it is advisable to speak with experts who are familiar with koi and can advise on general and specific health care issues.

The setting up and maintenance of a koi pond does involve time, energy and expense - but it is well worth making the effort as the results are unbelievably rewarding. These are beautiful fish and provide hours of fun for friends, family and visitors.