1. Reason: When the temperature in the fish tank is too low, it is extremely easy to breed small melon worms, and small melon worms will look for hosts. When they are parasitic on the lotus lantern fish, there will be white dots on the surface of the fish.

2. Treatment method: Raise the water temperature in time. You can choose two heating rods with better quality, put them into the fish tank, and use a thermometer with better quality. Observe the temperature change of thermometer, and it is advisable to increase it by 1-2 ℃ at a time. Gradually raise the water temperature to 30 ℃, and you can kill small melon worms.

1. Reason: If the small melon worms on the surface of fish are not treated in time, they may invade other lotus lantern fish, resulting in white spot disease. Fish already suffering from white spot disease may die if they are not treated in time.

2. Treatment method: The lotus lantern fish suffering from white spot disease should be salvaged from the fish tank in time to prevent them from transmitting diseases and insect pests to other fish. At the same time, it is necessary to spray pesticides into the fish tank. Use according to the instructions. Insecticides should not be used frequently to prevent damage to fish itself. Spray it once or twice a week for half a month, and stop using it after the white spots on the surface of small melon worms disappear.