1. Animal feed: Animal feed mainly includes fish and insects, Cyclops, water earthworms, paramecium, wigglers and so on. This kind of food can survive for a long time in the fish tank, which can stimulate Koi's interest in eating. This kind of feed also contains a lot of protein, vitamins and other nutrients, which can promote the hair color and growth of koi.

2. Plant feed: Although animal feed is the main feed for koi, there should also be a proper amount of plant feed, such as weeds and aquatic plants. This can ensure the balance of nutrition, which is beneficial to its growth, but it cannot be fed this feed for a long time.

3. Synthetic feed: Synthetic feed is rich in protein, sugar, vitamins, inorganic salts and fat, which can ensure the normal growth of koi. Eating these foods can also enhance the resistance of koi fish, so that they are not easy to get sick. Furthermore, eating this kind of food will make koi fish's hair color more uniform and make their gonads develop more soundly.

Feeding koi usually takes three times a day, once in the morning, once in the evening, and the interval between each feeding must be long enough so that the fish can digest well. In addition, we should control our food intake, and ensure that the fish are eaten within 3-5 minutes every time we feed. For the residual bait that has not been eaten, it is best to clean it up, so as not to pollute the water environment and be harmful to the health of fish.