1. Reason: The rotten tail and scales of map fish may be caused by poor water quality, and their metabolism speed is relatively fast, and the water quality is seriously polluted. When the water quality of feeding deteriorates, they will have rotten tails and scales.

2. Solution: Breeders need to change water immediately to keep the water clean. If there is a filter, it is necessary to open the filter to the maximum to slow down the deterioration of water quality.

1. Reason: The rotten tail and scales of map fish may also be bacterial infection. For example, if their tails or fins are not treated in time after trauma, it will lead to bacterial infection. There is also the poor water quality, more bacteria breed in the water, and they will also have rotten tails and scales.

2. Solution: Breeders need to immediately transfer map fish to a new fish tank, because bacterial infection may spread to other fish, so sick fish need to be farmed separately. After being transferred to a separate fish tank, the breeder needs to use potassium permanganate solution to give the sick fish a medicated bath.

1. Reason: The rotten tail and scales of map fish may also be suffering from rotten tail disease, which is caused by trauma or poor water quality.

2. Solution: The breeder needs to use oxytetracycline or malachite green solution to give the sick fish a medicinal bath. If the rotten tail and scales are serious, the breeder needs to apply malachite green to the wound.