It may be a normal physiological phenomenon that koi fish changes color when raised, or it may be dyed and faded, or it may be due to improper feeding. It is normal for koi fish to gradually change color, become more and more beautiful and enrich its colors during its growth. However, if the color gradually fades, it may be dyed, and this process is irreversible, so it is best to buy koi in regular businesses. In addition, heat preservation and oxygenation should be recalled during feeding.

1. Feeding: Koi does not feel full, so it will eat as much as it feeds, and it is easy to die if it feeds too much. Usually, it is enough to feed once a day. Feed can choose red worms, carrots, fish feed, etc., and general fish food on the market can also be fed to it.

2. Change water: Koi fish lives in water, and impurities from excrement and body will naturally fall off directly in the fish tank. During maintenance, it is necessary to change water frequently to avoid pollution caused by excessive impurities. Usually, it is enough to change water once a week. If koi fish is sick, it needs to change water every other day.

3. Fish tank: When choosing a fish tank, it is necessary to decide which fish tank to use according to the size and quantity of koi fish. If it is a small koi, you can use a round cylinder, and the material can be glass. If it is a large koi, you need to customize the fish tank or use the ground tank. The safety of ground tank and customized fish tank is relatively high, which is suitable for breeding large koi fish. In terms of materials, it is necessary to choose materials with high hardness.