1. Reason: The drooping tail of goldfish may be due to the poor water quality. Although they do not have high requirements for water quality, living in an environment with poor water quality for a long time will lead to more discomfort.

2. Solution: Breeders need to change water for goldfish regularly to keep the water clean. If conditions permit, it is best to install a filter to slow down the deterioration of water quality. Usually, the amount of water change should not be too large, and it is best to control it at one third of the total amount of water.

1. Reason: The drooping tail of goldfish may also be caused by the low temperature, although they can accept the water temperature between 0-38 ℃. But if the temperature is too low, their activity will be affected, and their tails will droop.

2. Solution: It is best for breeders to install a heating rod to keep the water temperature in a stable range. As long as the water temperature is constant, their activity will naturally increase. However, the heating speed should not be too fast to avoid more discomfort.

1. Reason: The sagging tail of goldfish may also be caused by natural aging. When goldfish is older, its activities and body shape will be affected. The obvious ones are tail drooping and decreased activity.

2, Solution: This kind of thing is a natural phenomenon, and breeders can't solve it. Just make sure they live in a comfortable environment and let them grow old naturally.