AquaDoc Bromine Booster for Hot Tub and Spa - 16 oz - Sodium Bromide to Establish Bromide Reserve - Compatible with Bromine Tablets - Made in USABrand: MAV AquaDoc Features: Builds Bromide Reserve for Spa Water AquaDoc Bromine Booster adds sodium bromide to hot tub and spa water to establish a bromide reserve. This is a required step before using bromine tablets when filling or refilling your spa. Works With Hot Tub Bromine Tablets Add this booster before introducing spa bromine tablets for the first time, or whenever your spa or hot tub is drained and refilled, to properly prepare your water