GLB Pool and Spa Products 71238 2-Pound pH Down Pool Water Balancer Sanitizer lowers ph level in swimming pool water Aids in preventing staining&#44; scaling and clouding of pool water Works most efficiently when ph is kept in proper range Allow 6 to 8 hours for distribution throughout the pool and then recheck the ph Compatible with chlorine&#44; bromine&#44; ozone&#44; biguanide sanitizers and salt water pools When pH value rises above 7.8 while pump is in operation, disperse 4-ounce (1/4-pound) for each 10, 000-gallon of water into the deep end of pool Allow 6 to 8 hours for distribution throughout the pool, and then recheck the ph Sanitizers work most efficiently when pH is kept in proper range Comparable with chlorine, bromine, ozone, biguanide sanitizers, and salt water pools Measures 9.3-inches in length by 3-inches in width by 2.7-inches in height