Most consumer window cleaning products are formulated for light indoor use — fingerprints, dust, and cooking grease. They’re not designed for the conditions Naples glass faces: salt air corrosion, calcium and silica mineral deposits from hard water, and the organic film that builds up from Gulf-area humidity. Here’s what actually works for each type of contamination.

For Light Dust and Fingerprints (Interior)

Any ammonia-free, pH-neutral glass cleaner works well for interior surfaces without coatings or film. Apply with a microfiber cloth, work in sections, and buff dry before it dries on its own — in Naples’ heat, solutions dry fast and streak if you let them sit.

For Salt Deposits (Exterior)

Salt deposits require a surfactant-based solution with adequate dwell time — typically 30–60 seconds on the glass before wiping. Professional window cleaning solutions contain higher surfactant concentrations than consumer products. For DIY exterior work, a few drops of dish soap in purified water (not tap water) applied with a soft brush is more effective than any spray product.

For Hard Water Mineral Deposits

This is where consumer products universally fail. Calcium and silica deposits require a diluted acid treatment — typically oxalic, citric, or hydrofluoric acid at low concentrations with controlled dwell time. Products like CLR or Bar Keepers Friend (oxalic acid) can address light mineral buildup on uncoated glass, but heavy deposits require professional-grade mineral removers applied with proper technique.

Never use abrasive scrubbers on glass for mineral removal — they scratch. Chemical treatment is the only safe approach for hard deposits.

The Most Important Variable: Your Water

No cleaning product performs well if you rinse with Naples tap water. The minerals in the rinse water deposit on the glass as it dries, partially undoing your work. Purified water — from a reverse osmosis filter, deionized system, or store-bought distilled water — for the final rinse makes a measurable difference in results.