There are many factors affecting Betta fish to change water every few days. The most important thing is whether there is a filtration system in the fish tank. If there is no filtration system in the fish tank, it is necessary to change the water frequently and change the water once every 3-4 days. If there is a filtration system in the fish tank, the interval of water change can be extended.

There are filter screens, activated carbon, nitrifying bacteria and other substances in the filtration system, which can physically, chemically and biologically filter the water in the fish tank respectively. Generally, water can be changed once every 1-2 weeks. In addition, the feeding density will also affect their water change time. When the feeding density is too high, the water is particularly easy to deteriorate, so it is necessary to shorten the water change time.

When raising betta fish, changing water is a common process. When changing water for them, first take some tap water or well water and put it in a clean container. If it is tap water, you need to expose it to the sun for several days or remove chlorine with baking soda. Then check the temperature and PH in the fish tank with thermometer and PH meter respectively, and adjust the temperature and PH of the new water to make them similar to those in the original fish tank. Finally, take out a quarter of the water in the original fish tank and pour the water in the new container. When pouring, pay attention to pouring slowly. If pouring too fast, it will scare the fighting fish.