The pH128 GroPro is a pH tester with advanced features for the measurement of pH in hydroponic nutrient solutions. The pH128 is a very simple meter to operate with all functions including turning on/off and calibration are performed with a single button. The pH128 features a replaceable HI1271 pH electrode that can be changed when needed without having to buy a new meter. The pH128 is supplied complete with a carrying case and calibration solutions.