1. There is too much chlorine gas: Zebrafish die when changing water may be due to water quality problems, and many breeders will use tap water just received. However, tap water contains a lot of chlorine. If it is used without drying in advance, the chlorine in water will affect their health, so zebrafish will die every time they change water.

2. High frequency of changing water: Zebrafish dies when changing water, probably because the frequency of changing water is too high. Many breeders change the water once every 1-2 days in order to clean the water in the fish tank. Frequent water change will make the water quality in the fish tank extremely unstable, which is also an important cause of zebrafish death.

3. Large amount of water change: Zebrafish may die when they change water. Although they have strong adaptability, they cannot accept sudden changes in the environment. If the amount of water change is too large, they will have stress reaction or die.

Zebrafish change water according to their habits, and their pollution to water quality is not serious. If there is a filter pump, you can choose to change water once a week, and the amount of water change each time does not need to be too large, and it can be controlled at one third of the total water quantity. Before changing water, tap water should be exposed to the sun for 2-3 days, so that chlorine in water can be completely volatilized. In addition, pay attention to the temperature difference between new water and old water not exceeding 2 ℃.