Description50 Strips. Testing for: Chlorine, pH, Alkalinity and Calcium HardnessThe Insta-Test 4 pool & spa strip measures Free Chlorine 0-10 ppm (or Bromine 0-20 ppm), pH 6.2-8.4, Total Alkalinity 0-240 and Total Hardness 50-800 ppm.This test strip is a 1-Dip method designed to match the way strip users actually test water. Just dip and read to get truly instant results—only by Insta-TEST!No swirling or waiting times: the new Insta-TEST 1-Dip formula features extremely stable color reactions without cross-contaminated pads.50 Strips Per Bottle