The Butterfly Koi is the hybrid cousin of the traditional koi. Its long, flowing fins resemble the colourful wings of butterflies, making for an aesthetically pleasing look. Butterfly Koi are often kept as ornamental fish for this reason. While traditional koi were developed in Japan in the 19th century, Butterfly Koi were hybridised only a few decades ago. These fish can grow up to 36 inches in length and are fairly easy to care for, provided you have the right equipment. Butterfly Koi can be maintained in the same fashion as traditional koi.
Put your Butterfly Koi in a pond that holds at least 1,000 gallons of water and is more than a meter in depth. Small Butterfly Koi can be kept in large aquariums, though it is not their preferred environment. All types of koi prefer to have ample space in which to swim.
Add sturdy-rooted plants to the pond. Koi tend to nibble on plant roots, so you should encircle the plants with stones to help minimise damage.
Keep the pH of the pond at a neutral 6.8 to 7.2 range. If you use a concrete pond, keep in mind the materials of the concrete will cause the pH level to naturally rise. You can use a coating on top of the concrete to reduce this effect.
Feed your Butterfly Koi high-quality pellet food with no more than 30 per cent protein. An occasional shrimp treat is fine, but pellet food ensures a balanced diet. Feed them one to two times a day during the hot seasons and less during the winter months. Do not overfeed your koi as leftover food can change the balance of the pond. If the Butterfly Koi cannot eat all of the food you give them quickly, you are overfeeding them.
Install a heater. Butterfly Koi are cold water fish, but too much cold can be lethal. Koi can handle temperatures between 0.556 and 32.2 degrees Celsius. If you live in a place where temperatures fall below 33 degrees, a heater will keep your Butterfly Koi from freezing to death.
Pin a string net above the surface of the pond to help protect your koi from predators. The bright colours of the Butterfly Koi sometimes attract unwanted attention.
Do not overstock your pond. Koi tend to panic and fight over food and oxygen if they feel overcrowded. They prefer to swim around without having to compete for space.