Test the salt level in the pool - Salt range: 0~9990 ppm / 10~100 ppm; Check the salt concentration in saltwater pools and spas that use a salt chlorinator; It helps the salt chlorinator work more efficiently with the appropriate salinity level. Test the pH level in the pool - pH: 0.00 ~ 14.00; We recommend a pH level between 7.2 and 7.8 depending on the type of pool (fiberglass, vinyl, and tile). When the pH value is back within range, optimal performance and cleaner water are achieved. Test strips vs. digital meter - With test strips, you have to guess the pool's value based on the color of a strip; however, the digital meter provides an accurate reading, so no guessing is required. In addition, using enough test strips will increase your cost with long-term use. Multifunctional salinity meter: The ORAPXI 5-in-1 tester can measure salinity/pH/TDS/EC and temperature level, suitable for most spas and saltwater hot tubs. Easy to use: All you need to do is immerse the tester in your pool water, and the LCD screen will show the measurement result in seconds.