It also features automatic temperature compensation, easy calibration, and flip top battery compartment. The Oakton pHTestr series of pH pens test the pH value of your nutrient solution. The SalTestas dual reading modes let you take continuous multiple readings or a single reading. The Gro Chek has an easy to read LCD display. These continuous read meters take the guesswork out of growing.
All models are waterproof and have a two year warrany.