Hot Tub Spa Chemical Balance Pack: Alkalinity Up, pH Increaser, pH Decreaser, Calcium Increaser Alkalinity Up: Raises low total alkalinity (TA) to reduce corrosion, prevent pH bounce. 1 lb. pH Increaser: Raises low pH to prevent corrosion, optimize sanitizer effectiveness, reduce eye irritation. 1 lb. pH Decreaser: Lowers high pH and TA to prevent scale buildup. 1.5 lbs. Increase Calcium: Raises low water hardness to prevent corrosion, reduce foaming. 14 oz. STOCK UP & SAVE!!