1. Reason: The black scale of dragon fish may be caused by too much water quality fluctuation, and they are very sensitive to the change of water quality. If the breeder changes their water too much or too often, their scales will change.

2. Solution: Breeders need to keep the PH value between 6.5 and 7.5, and change their water regularly and quantitatively. It is best to change water once every 3-5 days, and the amount of water changed each time should be controlled at one third of the total amount of water.

1. Reason: The scale of dragon fish is black, which may be caused by the temperature difference, and they are also very sensitive to temperature changes. When the water temperature in which they live has changed greatly, their scales will also turn black.

2. Solution: Breeders need to use heating rods to keep the water temperature between 28-30 ℃. When changing water at ordinary times, pay attention to the temperature difference between new water and old water not exceeding 2 ℃.

1. Reason: The black scales of dragon fish may also be due to improper feeding. Although they prefer to eat some loaches, too many loaches will cause their body color to turn black.

2. Solution: Breeders need to reduce the feeding amount of loach or other scaleless fish, and feed some centipedes, shrimps, red worms and other foods to increase their body color.