To most people a water garden simply would not be complete without fish swimming through the water. Whether we keep fish for their bright shimmering colors, the movement in the water, or for the more practical reasons such as mosquito control, fish are an important addition to a pond. Some of us name our fish and care for them as we would any other pet.

Koi ponds are ponds used for holding koi, usually as part of a landscape. Koi ponds can be designed specifically to promote health and growth of the Nishkigoi or Japanese Ornamental Carp.

The architecture of the koi pond can have a great effect on the health and wellbeing of the koi. The practice of keeping koi often revolves around "finishing" a koi at the right time. The concept of finishing means that the fish has reached is highest potential. A koi pond is different from a water garden because  Koi limit the amount of plant life available to be grown. Simply put: koi eat some Plants. A koi pond should also be larger because koi get quite large despite the size of the pond, it is recommended that a koi pond be no less than 1000 gallons in volume, the bigger the better. It also needs to have an area of the pond at least 3 feet deep, 4  5 may be better. Most ponds will be enjoyed more if they are installed close to the home. Select an area where you can see the pond year round. Ponds are great attracters of wildlife including birds and butterflies.The sound of running water adds greatly to the enjoyment of the pond.