Pond Salt is one of the great essential elements you can add to your pond to help improve the slime coat on your fish, relieve stressful injuries from transport and can be used to fight off harmful parasites. Use one to two pounds of pond salt per 100 gallons of pond water for mild medicinal stress relief situations and to help restore electrolyte balance. Use three pounds per 100 gallons when treating for disease or parasites. 2% salt will not harm aquatic plants. Use as hydrometer to measure salt levels in your pond.