Take a clean, dry glass. Fill it with tap water and let it sit out overnight. In the morning, don’t drink it—look at it.
If you see a white, powdery film on the glass, that’s hard water leaving its nasty calling card. If the glass looks clear and spotless, you’ve got soft water. Easy peasy, lemon squeezy.
Pro tip: If your glass looks like a snow globe threw up on it, you might want to consider a water softener. Your future coffee cups will thank you.
