The Alkalinity Checker HI755 from Hanna Instruments is a small and effective tool that allows you to monitor the alkalinity in saltwater tanks. It uses the colorimetric method in order to provide you with very accurate readings from +/-5 ppm +/- 5%. Each type of checker from Hanna is designed to monitor only a single parameter, which is what allows them to be so precise in their readings.

Like all other handheld colorimeters from Hanna Instruments, this one is capable of accuracies normally found only with expensive professional instrumentation, but it is very affordable just like the traditional chemical test kits. It bridges the gap between the two in order to provide the most convenient tools around.

In order to use the device you need to follow a few simple steps. First you need to add a water sample to the cuvette which is included in the kit. Then you need to use it in order to zero out the checker. After that remove the sample and add the reagent, then place it back in the checker. After you press the button you will receive an immediate accurate reading.

The checker has been designed so that it is portable. It only weighs 64 grams so you can take it anywhere with you and provide instantaneous readings. It has a large LCD display that features easy-to-read digits and it only takes one button to operate it. It has an auto shut off feature that activates after 10 minutes of inactivity. It uses one AAA battery. The standard Alkalinity Checker kit comes with 2 cuvettes with caps, 1 syringe, 1 bottle of alkalinity reagent, battery and instructions.