Windex vs Vinegar: The Short Answer
Windex-style ammonia cleaners streak badly in direct sun and struggle with hard-water spotting, while a vinegar-and-water rinse cuts mineral deposits better but leaves a faint film on exterior glass if you don't dry it fast. Neither fully solves the salt film on coastal glass or the sprinkler spotting on inland glass the way a plain, mineral-free rinse does.
Last updated: September 2026
We get asked this a lot on jobs in Poway and Rancho Peñasquitos, where sprinkler overspray leaves the low corners of a window covered in white mineral spotting that never seems to fully wipe off. Last month on a two-story home in Rancho Bernardo, we squeegeed 38 panes and every ground-floor window on the sprinkler side had that same chalky ring.
Is Windex or Vinegar Better for Windows?
Windex works fine indoors on a small mirror or a shower door. Outdoors, in direct San Diego sun, the ammonia flashes off too fast and leaves streaks before you can buff it out. On glass with existing hard-water spotting, it does nothing to break down the mineral deposit itself.
Vinegar's acidity actually dissolves calcium and mineral buildup, which is why it works better than Windex on sprinkler spotting. The tradeoff is smell, and the fact that a vinegar rinse still leaves whatever minerals are in your tap water behind once it dries, unless you dry every pane by hand immediately.
| Method | Good for | Falls short on |
|---|---|---|
| Windex / ammonia cleaner | Small indoor glass, mirrors | Streaks in sun, doesn't touch mineral spotting |
| Vinegar and water | Light hard-water spotting | Leaves tap-water minerals behind unless hand-dried fast |
| Deionized water | Exterior glass, salt film, sprinkler spotting | Requires a water-fed brush setup, not a spray-bottle job |
Why We Use Deionized Water Instead
Deionized water has nothing dissolved in it. No calcium, no salt, no minerals to leave behind once the water evaporates. That's why exterior glass dries completely clear with no squeegee pass at all, even on a west-facing window taking direct afternoon sun. We run it through a water-fed pole system at around 40 PSI, which is enough flow to rinse a full two-story elevation without ever climbing higher than the gutter line.
On coastal jobs in La Jolla and Del Mar, that matters because the salt film off the ocean reacts differently than inland dust. Rinsing salt with regular tap water just trades one mineral deposit for another, which is the same problem as using vinegar on it. Deionized water is the only rinse that actually leaves nothing behind.
For a quick spot-clean between visits, vinegar and water is a reasonable stopgap. For the exterior glass itself, especially anywhere near the coast or near sprinklers, it's not a substitute for a proper rinse. Our standard exterior package starts at $175 for a typical single-story San Diego home, and deionized water is included, not an upcharge. See our exterior window cleaning page for how we handle it.