Material The pH meter is made of plastic shell, which is durable and sturdy. And it has a large screen which shows the test result of pH and chlorine level for reading easy and precise The pH value is one of the most important factors in pool water balance and should be tested and corrected at least weekly. The pH value is the measure of acidity or alkalinity of pool water.Chlorine, which kills bacteria, algae and microorganisms. It cannot be used in salt water Note Too little chlorine leads to the growth of algae and bacteria, waterborne diseases, cloudy water and poor water hygiene. Too much chlorine can cause eye, nose and skin irritation. rememberalso that chlorine in the pool is carcinogenic and we must strive to keep its level to the minimum necessary for complete disinfection Wide application The pool pH test is widely used for measuring drinking water, aquariums, swimming pools, tap water, hydroponics, spas, laboratories and scientific testing Applicable items The pool water tester is specially designed for family sized swimming pools or spas. The pH tester is the perfect little tool for home and laboratory pH testing applications Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.