What causes hard water spots
Hard water carries dissolved minerals, mostly calcium and magnesium. When that water lands on a window and dries, the water evaporates but the minerals stay behind as the cloudy white spots you see.
In Los Angeles the most common source is sprinklers and irrigation overspray hitting the glass, along with rain that picks up minerals and dust. Left through the hot dry season, the spots harden and become much tougher to remove.
How to remove fresh spots
If the spots are recent, you can often remove them yourself with a mild acid that dissolves the minerals.
- Mix equal parts white vinegar and water
- Soak a cloth and hold it on the spots for a few minutes to loosen them
- Gently scrub with a non abrasive pad or microfiber cloth
- Rinse thoroughly and dry with a clean microfiber cloth
- Repeat on stubborn areas rather than scrubbing harder
When spots have etched the glass
Minerals that sit on glass for months can etch into the surface, leaving a haze that a normal cleaner will not remove. At that stage the damage is in the glass itself, not on top of it.
Professional treatment with the right products can often restore etched glass, but severe cases may be permanent, which is why treating spots early matters.
How to prevent them coming back
Prevention is easier than removal. A few adjustments keep hard water off the glass.
- Aim sprinklers away from windows and adjust overspray
- Water in the early morning so glass is not baked in the sun
- Wipe down windows that regularly get hit by irrigation
- Schedule regular professional cleaning before spots harden
Related services
Ready to book, or want an exact figure? Explore the services in this guide:
Related reading
Keep reading on closely related topics: