1.Attention: immerse the probe only in the pool or hot tub water. Please turn the switch to the closed position when not in use. Store the tester in a cool and dry place. Cleaning accessory. Cleaning accessory meter portable pH. 2.Easy to use: read the instructions carefully, you will master the operation quickly. Different test situations have different rules. Whether it's a public swimming pool, a spa or a villa with swimming pool, this instrument is perfect. Cleaning accessory. Cleaning accessory. 3.Precise reading: a large screen for quick and accurate display of pH and chlorine values, you can easily read the result. Cleaning accessory. 4.UseBefore using this tester for the first time, you need to adjust it to your swimming pool or hot tub water in the following order: 1.Test your pool or spa water with a conventional liquid test kit.3. No adjustment is required for the pH value. Water quality monitor pH tester chlorine.