Help keep the water in your pool or spa fresh by using these easy-to-use test strips to monitor for free chlorine, -PH and alkalinity. Just compare the test strip to the easy-to-follow colour guide. Test strips are used to maintain the correct values in pool water. They are used to measure the free chlorine, pH and alkalinity of pool water.They measure the amount of free chlorine worth 0-10 ppm, alkalinity of 0-240 ppm and a pH value of 6.2-8.4 with the current display.The package contains 50 water control stripsBestway' Flowcleara Pool and Spa Test Strips ensure the right chemical balance of your pool or hot tub. With the 3-in-1 test strips you can test: -Free chlorine content -pH -alkalinity Using the color indicator system, you know immediately which chemicals to adapt. The strips measure the free chlorine content of 0-10 ppm, the alkalinity of 0-240 ppm and the pH of 6.2 to 8.4 with immediately readable results. The package contains 50 test strips with a shelf life of 18 months.Fea