[7 in 1] Swimming pool test paper for qualitative and semi-qualitative water quality testing, mainly for detecting elements: PH, total alkali, nitrite, residual chlorine, total chlorine , hardness, bromine. [Quick measurement] Immerse the reaction area of the test paper in the test solution for 1-2 seconds, take out the test paper, and wet the excess water with the paper. Hold it horizontally for 30-60 seconds to read data (less 30 seconds or more than one minute will not be accurate). Compare the test strip to the color chart on the bottle. [Easy to carry] The test strips come in small bottles. One vial of test strips contains 50 test strips. It is small in size and very convenient to carry. It is the best tool to test the water quality when you're on the go. Healthy Water Quality: Test strips are very important to measure the water quality of swimming pools and hot springs. Pools and spas should be tested at least twice a week to ensure their quality. A quality water makes life healthier and safer. Wide ApplicationThe test strip can be used in drinking water, swimming pools, hot springs, ponds, aquariums and industrial waste water.