2-Pack AquaChek Total Hardness Test Strips for Pool & Spa Water - 2 x 25 ct. bottles (50 tests total) Total Water Hardness - Spa, Pool, or household water testing Calcium + Magnesium Levels Low Range (up to 120ppm) High Range (from 250 to 1,000ppm) Two 25-count bottles (50 tests total)