1. River water and lake water: When raising goldfish at home, you can choose river water and lake water. Because these two kinds of water are natural water, raising goldfish with these two kinds can better restore the wild environment. But now these two kinds of water are vulnerable to pollution, and breeders need to confirm whether they are contaminated when using them.

2. Well water: If river or lake water is not available, you can choose well water to raise goldfish. Because well water also contains more minerals, it can provide more help for the growth and development of goldfish. However, the temperature of well water is relatively low, so breeders need to adjust their temperature to the same as the feeding temperature before using it.

3. Tap water: Tap water is not the most suitable for goldfish, but tap water is easy to obtain and clean, so many breeders will choose to use tap water to breed goldfish. The tap water just received contains more chlorine. Although it is not harmful to human body, it has certain influence on goldfish. Breeders need to expose them to the sun for a period of time before using them.

The frequency of goldfish changing water can be determined according to the water temperature they live in. If the water temperature they live in is on the high side, it needs to change water once every 3-5 days. If the water temperature in which they live is low, the breeder can change the water once every 7 days or so. In addition to water temperature, breeders can also change water according to water pollution. If the water pollution is not serious, the frequency of water change can be reduced. If the pollution is serious, it is necessary to increase the frequency of water change.