7-in-1Swimming pool test strips, used for qualitative and semi-qualitative water quality testing, mainly for testing Total Chlorine, Bromine, Nitrite, Nitrate, Hardness, Total Alkalinity, PH. Quick MeasurementJust soak the test strip in water, pull it out after 2 seconds, then compare the color with the range on the vial label to see the result. 50 piecesWater quality testing should be done twice a week, there are 50 test papers in a bottle, please close the lid tightly and keep always the desiccant in the bottle. Do not touch any area of the test pad on the test strip. Easy to CarryTest strips are packed in small bottles, very convenient to carry, it is the best tool to test quality water coming out. Scope of applicationSwimming pool test strips can be used for drinking water, swimming pools, spas, ponds, aquariums and sewage industrial, etc.