www.hannainst.com

The alkalinity tester es great. The nitrate and calcium ones need to be simplified

Not to happy with the product. Needs to much calibration every time when you switch it on it’s taking time to calibrate. After calibration it is more than 5 DO out from my other meter no idea how to correct it. Shipping was excellent ,

Okay!

Use better or stronger cabling, or I won't be buying another probe.

Make the catch that opens the hinged unit bigger. We could not do it by hand and had to use a flat head screw driver to be able to open it each time. A 5x deeper 'lip' would work far better.