The goldfish's body surface may appear to be covered with a layer of frost for the following two reasons: 1. The water contains chlorine. When changing the water for the goldfish, do not use tap water directly. If you change the water directly with tap water, there will be a large amount of chlorine in the water, which will affect the surface of the goldfish. It looks like there is a layer of frost; 2. Goldfish is sick. Generally, a layer of hoarfrost will appear on goldfish suffering from saprolegnia or white spot disease.

Tip:

When changing the water for goldfish, you should leave the tap water for 1-2 days to evaporate the chlorine in the water before changing the water. This can also effectively remove the bleaching powder in the tap water. If a goldfish is suffering from saprolegnia or white spot disease, it should be isolated and treated immediately to prevent it from being transmitted to other goldfish and causing the disease to spread.