Koi eat a very wide range of food including both plant and animal species. Like other members of the carp family, they tend to be bottom feeders. Koi pet food tends to come in pellets that are formulated to contain all the nutrients that they need to remain healthy. However, Koi are versatile animals and their diets can be supplemented with a range of other human foods, often leftovers from our own meals. These popular ‘supplements’ include brown bread, prawns, cockles, sweet corn, oranges, cheese, lettuce and others. However, the amount of these foods should be kept to a minimum so that the Koi eat sufficient amounts of their own specially formulated pellets. In addition, excess organic matter can quickly contaminate a pond, so control has to be exercised as to how much is used.
Koi will also feast on natural foods, such as Rotifers that are present in almost all external bodies of water, together with Algae and some weeds. In addition, Koi will consume Infusoria and Daphne, as well as bloodworm, snails and mosquito larvae. Interestingly, reducing the quantity of their pelleted diets will induce them to sift though the bottom of the pond for Algae and live food.