For and instant Bromine boost use Go Brom. No more waiting after re-filling your spa or hot tub! Add Go Brom to new fill water for an instant bromine residual. Just add bromine tablets or shock immediately after using Go Brom to activate. Reduces the amount of bromine and time it takes to reach the ideal bromine reading of 2 to 4 ppm (parts per million). Can also be used in conjunction with Renew Shock as part of a two part sanitation system that is completely chlorine free (for people with chlorine allergies). Active Ingredients: 99% Sodium Bromide. Recommended dosage is 1 ounce per 200 gallons of spa or hot tub water.