Desalination with light salt water. When the small salted fish is too salty, it can be desalted with brackish water, that is, the salted fish is soaked in 2% brackish water, and the high-concentration salt in the salted fish is infiltrated into the low-concentration brackish water by using the concentration difference between the two. Fish is a vertebrate living in water, usually with a flat body, spindle shape, many scales and swimming with fins.