There are many reasons for black koi to become white, which may be the deterioration of water quality, sudden drop of temperature, or lack of nutrition. According to different reasons, the coping methods are different. If it is caused by the deterioration of water quality, it is necessary to change water regularly to keep the water body clean and sanitary. If it is caused by sudden drop in temperature, it is necessary to control the water temperature, and a heating rod can be installed in the fish tank. If it is lack of nutrition, it is necessary to replace it with better feed.

1. Supplementing nutrition: If you want to prevent koi from fading, you must pay attention to supplementing nutrition and feed more animal feed or live bait. Usually, it should be fed two or three times a day, and the dosage should not be too much each time, so that it is easier to digest and absorb a small amount for many times, and it can avoid suffering from enteritis and other diseases.

2. Proper illumination: Fish farming must let it see the light properly, but the fish tank should not be placed in the sunny place, because if the illumination time is too long, it will easily lead to algae outbreak. Therefore, it is best to equip an aquarium special lamp in the tank, so that 6-8 hours of illumination can be added every day to prevent fish from fading.

3. Change water in time: No matter what fish is raised, even if the filtration effect is good, change water regularly, so as to avoid aging of water quality and make koi fish not fade easily. Usually, the water should be changed once a week, and the water quality is maintained well. It can be changed once every two weeks, with about a quarter of each time.