Keeping your water healthy isn"t difficult. Total Hardness Test Strips from AquaChek test for calcium and magnesium, which are the two minerals that primarily make up hardness in water. These test strips are much easier to use than cumbersome and expensive liquid test kits. Just dip an AquaChek Total Hardness strip in your pool or spa water for one second and remove it immediately. You get test results in seconds!