I ordered the water table filter of BWT. I wanted to test the water filter. I have a water ordered Amzon tester. We have a tap water, which corresponds to a hardness of 18. BWT filtered water 18 hardness is filtered so that when measuring a hardness of 10 herraus comes. The water is then not soft but hard means. From another review I read, that the filter after 2-3 weeks subsides. So not ideal. Or just ideal for people who have a hardness of funds from the line. So it is not to soften the best product to hard water