1. Reason: The black tail of parrot fish may be due to great changes in environment. Although they have low requirements for environment, they are sensitive to environmental changes. If the environment in which they grow fluctuates greatly, it will stimulate them. It makes them have more reactions, and blackening their tails is also one of the more common reactions.

2. Solution: Breeders need to keep the water temperature and water quality stable. If conditions permit, it is best to install a heating rod to keep the water temperature between 25-30 ℃. It is best to reduce the frequency and amount of water change, and wait for a few days, and the parrot fish will return to normal state.

1. Reason: Parrot fish's tail turns black. It may also be because they are too scared. They are less daring. Too much noise around them or suddenly turn on the lights will cause them to be frightened. After being frightened, the body and tail of parrot fish may turn black.

2. Solution: The breeder needs to keep the surrounding environment quiet and wait for the parrot fish to recover on its own. When the parrot fish recovers, the black on its tail will fade away.

1. Reason: The black tail of parrot fish may also be infected with black spot, and the main cause of this disease is poor water quality. Black spot disease is mainly caused by water mold and poisonous bacteria invading the body surface. Breeders need to find the wound on the tail of parrot fish before treating it.

2. Solution: After the breeder finds the wound of parrot fish, he can choose to apply crude salt or potassium permanganate solution to the wound. You can also directly sprinkle furacilin powder in the fish tank, which can alleviate black spot.