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. For the 271 covered cities: the utility's own published figure, as on the national rankings. Elsewhere: a planning estimate, labelled as one.
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.