You need to add salt when changing the water for goldfish, because salt has a sterilizing effect. You can add some salt every time you change the water. In addition, if the goldfish suffers from some diseases, it sometimes needs to be treated with salt. It is best to add coarse salt when adding salt. You also need to pay attention to the amount of salt added. Do not let the salt concentration of the water exceed 5 parts per thousand.

The effects of changing the water of goldfish and adding salt:

1. Enhance appetite. Putting a small amount of coarse salt in the fish tank can promote the digestion and absorption of fish, enhance their appetite, and make them more energetic.

2. Enhance immunity. It can also stimulate their physiological regulation, enhance their immunity, and stabilize their emotions.

3. Death from dehydration. Excessive salt is poison to them and will make the color of the fish lighter. In severe cases, it can cause them to die from dehydration. In addition, excessive salt will reduce the transparency of the water, which is also detrimental to the growth of aquatic plants.