Test the salt level in the pool - Salt range: 0~9990ppm/10~100ppm; Check the salt concentration of saltwater pools and spas that use a salt chlorine generator; It helps the salt chlorinator to work more efficiently with the proper salinity value. Test pool pH level - pH: 0.00~14.00; Recommend a pH level between 7.2 and 7.8 depending on the different types of pools (fiberglass, vinyl pools and tiled pools). When the pH is back in range, for optimal performance and cleaner water. Test Strips VS Digital Meter - With strip tests, you'll have to guess which pool value is based on the color of a strip; The digital tester, however, will give an exact reading, so no guesswork is needed. Additionally, using enough test strips will increase your costs in the long run. Multifunction Salinity Tester: ORAPXI 5 in 1 tester can measure salinity/pH/TDS/EC and temperature level, suitable for most spas and saltwater spas. Easy to use: all you need , you just need to immerse the tester in your swimming pool water, then the LCD screen displays the measurement result in seconds.