What it measures pH, TDS, Temperature, EC, and Salinity What it is A 5in1 meter (aka pH pen or pH tester) suitable for testing in applications such as hydroponics and gardening, pools, spas, aquariums, reef tanks, water ionizers, drinking water, boilers, and more Key features Supports 3point calibration and automatic identification Water resistant body Simultaneous temperature display Sleek design with a large LCD display Automatic Temperature Compensation ATC Datahold function Lowbattery indicator Use scenarios Hydroponics and gardening: monitor pH and EC in nutrient solutions to maintain plant growth, while tracking TDS and salinity to keep nutrient balance within the desired range Aquariums and reef tanks: keep water parameters stable for fish, corals, and other livestock by regularly checking pH, EC, and salinity, with temperature shown at the same time Drinking water and boilers: verify water quality for safe consumption and appliance performance by measuring pH, TDS, EC, and temperature, with quick indicators when readings drop or rise Performance notes All measurements are integrated in one handheld instrument for convenient, onsite testing Temperature measurements are accounted for automatically to ensure accurate readings across varying conditions The device features a durable, waterresistant body, easytoread display, and clear indicators for easy operation in typical testing environments