Water Quality TestAs one of the most important factors in pool water balance, PH is used to measure the acidity or alkalinity of water. And chlorine is used to kill algae, microorganisms, etc. They should be tested and corrected at least once a week. This 2-in-1 water quality tester feature allows you to quickly and accurately test pH and chlorine level without using chemicals. Handy ToolThe recommended chlorine level for swimming pools and spas is 1.2 to 1.7 ppm. The recommended pH level for swimming pools and spas is 7.2 to 7.8. This pH and chlorine tester is an indispensable tool, which can ensure that your pool or spa water is safe, comfortable and non-corrosive. Simple to useJust insert the cleaned metal probes into the water, slide the wheel on the face of the tester fully left (right) to CL(PH), and you can read the value. The scale is clear, accurate and easy to understand, which can save you more time and money, and make your pool easier to have a safe pH and chlorine level. Lightweight and portable This digital water quality detector is lightweight, easy to carry and easy to clean. A hole for placing the probe is designed on the side of the tester, which is convenient for storage and carrying without being too messy. Package included pH and CL2 probe tester 1, instruction manual 1, sandpaper 1