Koi are omnivores, and their diet consists of plants, insects, and small animals such as snails, worms, and crustaceans. They are also known to eat algae, which can help keep ponds clean.
Koi are generally peaceful fish, and they can live with other species of fish such as goldfish, catfish, and other carp. However, they should not be kept with aggressive fish, as they can be easily injured or killed.
Koi are relatively hardy fish, and they can tolerate a wide range of water temperatures and pH levels. However, they do best in water that is between 65 and 75 degrees Fahrenheit, and with a pH level between 7 and 8.
Koi can grow to be quite large, with some specimens reaching lengths of up to 3 feet. They typically live for 15-25 years, but can live for even longer in captivity.