White spot disease. When the Dutch phoenix suffers from this disease, white spots first appear on the fins, and the fish appear sluggish, floating on the water surface, and rarely moving. Or they often swim sideways and quickly rub off the itch beside aquatic plants and gravel. In severe cases, the fish will be covered with white spots, stop feeding, lose weight, have difficulty breathing, and even die.

First, raise the water temperature to 30 degrees to promote the production of spores on the surface of the fish Rapid maturation, accelerating their growth rate and causing them to fall off the surface of the fish. It can also be soaked in 5% saline for several days, or soaked in 2 parts per million (2ppm) methyl blue solution for 6 hours a day.