PondCare Pond SaltAPI Pond Pond Salt provides essential electrolytes fish need to survive with an all natural salt, made from evaporated sea water. Improves gill function, protects against nitrite toxicity and reduces stress. Provides electrolytes Improves gill function Protects against nitrite toxicity and reduces stress Helps to maintain a natural balance of electrolytes in the body fluids of pond fish. Can safely be used with all API Pond water conditioners,