Safety guarantee for water quality: the 7-in-1 test strip kit has been specially designed for hot tubs and hot tubs in the pool, which can provide quick and reliable results to check the water quality. Pool test strips can test total hardness, total chlorine, bromine, free chlorine, pH, cyanuric acid (stabiliser) and total alkalinity. Easy to use: the spa test strip for total water hardness and reliable results as well as simple and clear instructions (English language not guaranteed). Simply dip and compare to the large colour chart on the bottle. Pool test strips the desired area is marked on the bottle. Sealed packaging: the pool test strips are packed in a well-sealed jar for a longer storage time. After each use of the test paper, the bottle cap should be tightened in time to avoid contamination of the test paper with water. Wide application: these test strips are often used in swimming pools, spas, bathrooms, hot tubs and other water chemical tests. It is a good helper to quickly and accurately capture the water quality. Research has shown that your swimming pool should be tested at least twice a week.