Leisure Time Spa Test Chlorine Spa Test Strips 50 count (45010A) Keep your spa water balanced by making sure it is within the following recommended ranges: pH 7.2-7.8, total alkalinity 80-120 ppm and calcium hardness 150-400 ppm Available for chlorine and bromine sanitizing systems For more than 25 years, Leisure Time has been the premier name in spa water care Leisure time chlorine test strips 50 strips per pack Fast and simple It is very accurate Compatible with chlorine and ozone sanitizers