Review on PH Meter, TDS PPM Meter, Soil PH Tester - Digital Kit (3 Pack): Accurate Testing for Optimal Growing Conditions by Heidi Massine

PH. The counter is calibrated. many times. Constantly inaccurate. Tested with pH Power in distilled water and compared to a brand new "brand" pH meter. Using a water stir meter, the reading was +0.40 ish. If the device is idle, the pH value continues to rise. The other 2 meters are fine. *Water plants with incorrect pH up/down. Leads to pH blocking. A nutrient vampire in a plant. Brown spots, leaf curl, leaf fall. In my opinion, if you care enough about your plans, buy a counter. Spend a few dollars more. Buy a brand that has a guarantee.