comments:
Razgorths posted on r/hudsonvalley3w
If you just want to test for hardness, buy this API kit. It's $10, very accurate, and you'll have enough to test your house water basically forever. The reason why the "recommended" water testing places are $$$ is because they're testing for hundreds of different things at once, which is not the same as a salesperson coming to your house and waving a bunch of inconclusive test strips in your face. I would not suggest taking any "free in-home water tests" unless you really want to be put on a calling/mailing list and heavily advertised to.