Granular Bromine Booster is used to establish an immediate bromide bank or reserve upon initial filling of hot tub or spa. This provides for an adequate beginning bromide level when using bromine tablets in a float, which dissolve slowly over time. Product notes: Contains sodium bromide. Not a disinfectant by itself; must be used with your sanitizer. At startup add just 1/2 teaspoon per 100 gallons.