When changing water for goldfish, tap water cannot be used directly. The residual chlorine in tap water is toxic to goldfish. It may damage their gills and even cause the mucus on the fish's surface to shed, leaving them unprotected. Therefore, before using tap water to change the water for goldfish, it needs to be treated to remove the residual chlorine.
The following are the methods for treating tap water for goldfish water change:
Sun - drying method: Place the tap water in an open, ventilated area or on the balcony. With the circulation of air and the irradiation of sunlight, the residual chlorine in the water will volatilize. Usually, it takes 1 - 2 days of sun - drying. However, the sun - drying time should not exceed 3 - 5 days, otherwise the dissolved oxygen in the water will evaporate.
Static - standing method: If there is no condition for sun - drying, the tap water can also be left standing for 3 - 4 days to allow the residual chlorine to volatilize naturally.
Using a water purifier: A more convenient way is to use a water purifier with the function of filtering out residual chlorine. The filtered water can be directly used to change the water for goldfish.
In addition, the following points should also be noted when changing water:
Volume of water change: It is generally recommended that the volume of water changed each time is one - third, one - fourth, or one - fifth of the total water volume in the fish tank. Changing too much water may stimulate the goldfish.
Frequency of water change: You can change one - sixth of the tap water every day, which has little impact on the goldfish. However, the specific frequency of water change still needs to be determined according to the actual situation of the goldfish and the water quality of the fish tank.
Water temperature difference: When changing water, pay attention to the water temperature difference between the new water and the original water in the fish tank. If the water temperature difference is too large, it may cause a stress response in the goldfish. Therefore, before changing water, the new water can be placed near the fish tank to allow the water temperature to gradually approach that in the fish tank.
In conclusion, tap water cannot be directly used for changing water for goldfish. It needs to be treated to remove the residual chlorine first. At the same time, when changing water, factors such as the volume of water change, the frequency of water change, and the water temperature difference should also be noted to ensure the health of the goldfish.