TDS-EZ Water Quality Tester is as simple as 1-2-3. Calibration is easy: Simply press and the on/off button, place the probe in a calibration solution (included) and adjust using a mini screwdriver (not include). Accuracy is good enough +/- 3%.

I really like this controler. I use it with my calcium reactor in saltwater aquarium and also to control pH in freshwater planted tank.
The first reason why I chose to go with this model is because of it’s price. I could not find a better deal with other brands…

The PINPOINT® pH Monitor is in use by thousands of customers worldwide. This affordable unit remains the only full-time pH monitor with .01 resolution. The PINPOINT® pH Monitor is sold complete with probe and calibration fluids (9 volt battery not included). The electrode is also available separately and fits any meter, monitor or computer controller.

Pinpoint Salinity Monitor™ will accurately and immediately measure the amount of salt in any marine or freshwater system. The reading is fully temperature compensated, which is difficult or impossible with nearly any commercial hydrometer. The conversion chart will precisely show the corresponding density (specific gravity) or % salt (refractometer) values.

The Checker supplies you with fast and accurate readings from 0 to 14 pH with a resolution of 0.01 pH. This compact tester features a large easy-to-read LCD and a simple to perform 2-point calibration. The pH electrode of the Checker can be replaced; simply unscrew the electrode from the meter body and screw on a new one.