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.
At this hardness, mineral deposits begin etching the glass surface itself within 18 to 24 months of routine cleaning with tap water. The film is no longer "on" the glass — it has bonded to it. Distilled water for both wash and rinse, or invest in a deionizing filter cartridge that fits a standard hose.