Hard water leaves mineral deposits that look like permanent fog on glass. In Colorado — where water is moderately hard (50-150 ppm) and very alkaline (pH ~8) — these deposits etch into the glass surface within months if untreated. Sonlight removes hard water stains using a graduated approach: chemical treatment for fresh stains, cerium oxide polish for older, etched stains.
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Hard water stains can be removed if treated within ~6 months. Older stains may have etched the glass and require professional cerium oxide polishing.
Tech walks the property, photographs every affected window, and rates each pane fresh / older / etched / unrecoverable. Customer sees the assessment in writing.
Hydrofluoric-substitute acidic dissolver applied carefully — controlled dwell time, neutralizing rinse, full water rinse. Repeated up to 3 times per pane if needed.
Graduated polishing pads (1500, 2000, 3000 grit) with cerium oxide compound. Slow, careful work. Restores gloss to the glass surface.
Standard window clean to remove all polishing residue. Final inspection from inside and out, with photos of before/after.
Recommendation on sprinkler adjustments, future cleaning frequency, and any glass that needs replacement rather than restoration.
Every job is priced individually for the property — these are ballpark ranges to set expectations. The autoquoter on our home page returns an exact firm price for any address in our service area in 30 seconds.
| Profile | Price range |
|---|---|
| Light staining (1-3 windows) | $50–$100 add-on |
| Moderate staining (whole-home, fresh) | $150–$250 add-on |
| Severe etching (cerium oxide polish, per pane) | $30–$60 per pane |
| Whole-home severe etching | $400–$800+ |
| Permanent etching (replacement only) | Quoted per window |
Denver Water averages 50-80 ppm hardness with high alkalinity (pH ~8). The alkalinity is what etches glass — alkaline water dissolves silica faster than acidic water of the same hardness. Combined with 300+ days of sun, mineral deposits get baked into the surface.
Colorado Springs Utilities water averages 100-150 ppm hardness — about 2× Denver's. Hard water staining there sets in faster, especially on south-facing windows hit by sprinkler overspray.
Aurora Water is the hardest of the major Front Range suppliers (~120 ppm avg), which is why Aurora homes near lawn irrigation often have the worst hard-water staining we see.
Etching is permanent. The mineral deposits eat into the silica matrix of the glass and create microscopic pitting that scatters light. Once a window is etched (typically after 12+ months of untreated mineral exposure), no amount of polishing can fully restore it — only replacement will.
Yes — if caught within ~6 months. Fresh deposits dissolve with the right acidic chemistry. Stains older than 12 months may have etched into the glass; cerium oxide polish can restore gloss for moderate etching, but severe etching is permanent.
Run your fingernail across the cloudy area. Fresh deposits feel slightly raised; etched glass feels smoother than the surrounding clear glass. If you can see the cloudy area is below the rest of the surface (a slight depression), that's etching.
$50–$200 add-on to standard window cleaning for moderate staining. Severe etching requiring cerium oxide polish runs $30-$60 per pane. Whole-home severe-etching jobs range $400-$800+.
Sometimes — for very fresh stains less than 3 months old. Spray undiluted white vinegar, let it sit 5-10 minutes, scrub with a non-abrasive pad, rinse. For older or heavier deposits, you need a commercial mineral deposit remover or professional service.
Three steps: (1) adjust sprinkler heads so they don't hit windows, (2) install hose-end deflectors on sprinklers near windows, (3) get professional window cleaning twice yearly with a deionized-water rinse — DI water leaves no minerals behind.
Denver Water is moderately hard (~70 ppm) but very alkaline (pH ~8). Alkaline water dissolves silica in glass faster than acidic water of the same hardness. Combined with 300+ days of sun baking the deposits in, even moderate hardness produces visible staining within a single irrigation season.
Only if you also fix the cause. Replacement glass will be re-etched within 1-2 seasons if sprinklers continue to hit it. Fix the sprinkler pattern AND replace the glass — otherwise you'll be paying for replacement again in 18-24 months.
Yes. $2M general liability + Colorado workers' comp. The chemicals we use are industry-standard for glass restoration; we follow OSHA-compliant handling. Certificate of Insurance available on request.
Sonlight provides hard water stain removal across Colorado's entire Front Range — pick your city for local pricing examples, FAQs, and example homes:
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