WaterWorks™ Total Hardness (50 test strips) Tests Calcium & Magnesium Hardness from 0-1000ppm.

Best water testing strips out there.

The strips remain yellow regardless of the hardness of the water. Despite following the instructions carefully these do not work

Does what it says on the box. Tap water 450 ppm, softened water less than 10 ppm. A good test for checking that water softener is working.