[7-in-1]Swimming pool test strips, used for qualitative and semi-qualitative testing of water quality, mainly for testing Total Chlorine, Bromine, Nitrite, Nitrate, Hardness, Total Alkalinity,PH. [Quick measurement] Simply soak the test strip in water, remove it after 2 seconds, then compare the color with the range on the bottle label to see the result. [50pcs]Water quality analysis should be carried out twice a week, there are 50 test papers in one bottle, please close the lid tightly and always keep the desiccant in the bottle.Do not touch any area of the test pad on test strip. [Easy to carry]test strips are packed in small bottles, very convenient to carry, it is the best tool for testing water quality when going out. [Scope of application]Swimming pool test strips can be used for drinking water, swimming pools, spas, ponds, aquariums and industrial wastewater, etc.