1. Water sickness. The body of Luohan fish appears to be attached to the cotton-like substance. It may be caused by poor water quality, or it may be caused by the injury of the surface body. Treatments such as antibiotics and antibacterials can be supplemented or treatments such as malachite green or methylene blue can be used.

2. Bad mouth disease. The mouth and gill cover of Luohan fish are like white cotton balls, which are gradually infested and rotted; loss of appetite, slow movement, and then death. Use tetrahedron, 13 mg or more per liter of water, and then put the diseased fish in the treatment box for about six to seven days, replace half of the water every day, and keep the original dosage.