Hot Tub Things pH and Alkalinity Down 1.25 Pounds - Keep Your Spa Water Properly Balanced Keep hot tub water in check. This product lowers pH and Alkalinity to obtain the proper balance! America's #1 Trusted Brand of Hot Tub Chemicals Safety Tested to Assure Quality, Guaranteed Performance Formulated Exclusively for Hot Tubs And Made from the Purest Chemicals Available Compare to Leisure Time Spa Down Make sure all equipment is OFF. Add 1/4 oz. (1-1/2 tsp.) pH Down for every 500 gallons of spa water. Turn ON circulation system for 30 minutes. Retest water. If pH is still above 7.8, repeat steps 1-3.