Pocket Water Quality pH MeterYou can use this small but powerful pocket pH meter device to measure pH in aquariums, swimming pools, garden ponds, bathtubs. The digital pH meter can also be used to measure drinking water, RO systems, spas, soap mixtures, wine, beer, or any other liquid. How to calibrate pH meter / TDS meter? 1. Add pH4.00 / pH6.86 / pH9.18 buffer powder to water and stir. 2. Press the ON / OFF button and adjust to pH mode. Place the electrode in the pH4.00 / pH6.86 / pH9.18 standard solution and wait for 5 to 10 seconds. 3. Press and hold the MODE / CAL button and release it after 6 seconds; wait for pH4.00 / pH6.86 / pH9.18 to flash 3 times until the reading no longer flashes, and the pH calibration is completed. Automatic Temperature Compensation Digital pH MeterNo longer need to pay attention to the temperature of the test liquid, the pH meter can accurately determine the pH value of the sample within the temperature range of 32F140F (0C60C), thus solving the inaccurate problem caused by the change of liquid temperature. TipsFor a better use experience, we recommend soaking the tds meter digital water quality tester in clean water for 5 minutes after receiving the product before starting calibration. Because if the customer uses it immediately for the first time, it may cause inaccurate readings. pH meter to improve water qualityThis pH/TDS meter can help you find out the value of highquality water. Water with equal pH and TDS levels is very suitable for people's daily drinking water needs. For plants and aquaculture animals, if they drink highquality water with pH and TDS values tested by this pH meter, they can grow faster and healthier.