HT pH/Alkalinity Increaser raised both pH and Alkalinity. With the use of spa test strips make certain to maintain your alkalinity between 80 to 150 ppm and your pH between 7.2 to 7.8 ppm. RECOMMENDED USE 1. Determine amount of add: If pH is between 6.8 to 7.2 add 1 oz. If pH is less than 6.8 add 2 ounces. 2. Turn OFF all pumps and blowers 3. Add pH/Alkalinity to spa water 4. Turn on filtration pump for 1 to 3 hours 5. Retest water after 3 hours 6. If pH is below 7.2 repeat procedure