Product review (2 stars): Does not work. I tried both and the reading ...
Does not work. I tried both and the reading of the TDS water tester is the same as the tap water. And I made sure the water tester works by testing water from a different filter where the reading was 0 PPM. After some research it looks like buying almost any brand of fridge water filter is worth only improving the taste, but the health-related properties of the water: look for the difference between INS 42 and 53.