The GroLine HI98118 pH/temperature tester is our latest pocket meter for measuring the pH of a hydroponic nutrient solution. This modern looking meter is only 0.7" thick and extremely ergonomic, fitting comfortably in your hand. The HI98118 has a very large easy to read LCD display that shows both pH and temperature along with calibration, stability and low battery indicators. All operations are simplified to two buttons. One is for turning the meter on/off and the other for automatic one or two point calibration.