Pondcare 156C 1/2 Gallon Pond Salt: * Natural fish tonic * Provide 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 by helping to maintain a natural balance of electrolytes in the body fluids of pond fish * Can safely be used with all PondCare water conditioners, filtration materials, medications and fish foods * 1/2 gallon