Enter your ZIP code. We pull regional water hardness data and tell you exactly what you're dealing with — and whether you can keep cleaning with tap water or need to switch to distilled.
US zip codes only. Sources: USGS Water Hardness Survey 2023, EPA municipal CCR data.
You are in the hardest band in North America. Phoenix, Las Vegas, parts of Texas and the upper Midwest. At this level, calcium carbonate precipitates out of any water that touches your glass and dries — the spots you see are essentially limestone, growing one molecular layer at a time. Tap water cannot be part of your final pass under any circumstance.