This portable Checker pH tester supplies you with fast and accurate readings on a large LCD. The pH electrode can be interchanged with any Hanna pH electrode with a screw connector. Measures pH in a range of 0.0 to 14.0 with a resolution of 0.1 pH. For general use such as aquariums, pools and ponds. Please note: When you receive your new Checker pH Meter, the electrode will be dry. It should be conditioned by soaking the tip in pH 7 buffer solution (sold separately) for a couple of hours. Then follow calibration procedure using one or two pH buffer solution values. See accessories below for optional pH buffers and other maintenance solutions.