API Aquarium SaltAquarium Pharmaceuticals Aquarium Salt is an all natural salt, made from evaporated sea water, promotes healthy gill function, reduces stress and loss of electrolytes. Used to improve the efficiency of medications and reduce the harmful effects of nitrite. Promotes fish health Improves gill function Adds essential electrolytesFor freshwater fish As a General Tonic and Stress Reducer: Add 1 rounded tablespoonful for every 5 U. S. Gallons (19 L), or 1 2