The Spa Selections Benefit Spa Selections Algaecide is an effective, non-foaming algaecide that, when used regularly, will prevent and kill green algae in spas and hot tubs. Directions for Use: This product works best when added in several places directly to spa or hot tub water, with the pump running. Continue to keep the pump running for at least 30 minutes after adding algaecide. Wait 15 minutes before entering the spa. Spas or hot tubs with heavy growth of algae must be cleaned prior to using this product. INITIAL DOSE: Add 1 fl. oz. per 400 gallons water. Initial dose is used upon filling of spa or hot tub. For visible algae growth or slimy interior, treat with “Initial Dose†and remove algae debris. For maximum effectiveness, drain and clean spas or hot tubs containing heavy algae growth prior to treatment. Drain and clean spa or hot tub at least once a month, or as needed depending on bather load. MAINTENANCE DOSE: After initial treatment, to keep your spa free of algae growth, add 1/4 fl. oz. per 400 gallons every 5-7 days. This algaecide can be used in conjunction with chlorine or bromine sanitizer systems.