Salt used in fish ponds can first play the role of sterilization and disinfection. According to the different proportion of salt used, the bacteria and fungi eliminated are also different. In addition, the wheel worms and oblique tube worms on the surface of fish can be eliminated, thus preventing the occurrence of some diseases.

Besides preventing fish diseases, it can also play a therapeutic role, but it is generally used as an auxiliary drug to treat diseases such as water mold. The reason why salt is used is that salt can promote the absorption of drugs on the surface of fish, so as to give full play to the drug effect.

Under normal circumstances, the osmotic pressure of fish is higher than that of fresh water, so water will naturally penetrate into it. However, if salt is added to fish ponds, the osmotic pressure of water will increase, which will reduce the kidney drainage burden of fish. However, the salinity must be properly controlled. If it exceeds the standard, it will cause water to seep out of the fish and make it dehydrate and die.

Salt under fish ponds can also purify water. Salt can increase the sample concentration in water, so that suspended organic particles condense into flocs and sink to the bottom of the pond, so that the water quality can be maintained, which is beneficial to the health of fish. At the same time, it can also reduce the consumption of oxygen in water, which can make fish breathe better.