Hard water stains on Las Vegas windows: a pro guide

If you've lived in the Las Vegas valley for more than a year, you've seen it. That white, cloudy haze creeping across your windows. Maybe it started around the bottom edges near your landscaping. Maybe your second-story bathroom window looks frosted even though it shouldn't be. That's hard water, and in this city, it never lets up.

We've cleaned thousands of windows across Henderson, Summerlin, North Las Vegas, and everywhere in between. Hard water stains are the single most common issue we deal with. Not dirt. Not dust (though we get plenty of that too). Mineral deposits from our tap water, baked onto glass by 115-degree summers.

Here's what's happening to your windows, what you can do about it, and when it's time to call a professional.

Why Las Vegas water is so brutal on glass

Las Vegas tap water measures at 304 parts per million (ppm) of dissolved minerals, about 18 grains per gallon, according to the 2024 water quality report. The "very hard" classification starts at 10.5 GPG. Our water is nearly double that.

The national average sits around 100–150 ppm. Vegas carries two to three times that load.

Our water flows from Lake Mead and the Colorado River, cutting through hundreds of miles of limestone before it reaches our taps. By the time it arrives, it's loaded with calcium and magnesium carbonates.

Every time that water touches your windows and evaporates, it leaves its mineral payload behind. In a city where water evaporates in minutes during summer, that process repeats constantly. Few places combine the mineral load, triple-digit heat, and low humidity the way Vegas does.

How hard water actually damages your windows

Most people don't realize hard water stains aren't just sitting on the surface. They're bonding to it.

When mineral-laden water evaporates off your window, the calcium and magnesium carbonates attach to the glass at a microscopic level. Early on, this bond is weak. A good cleaning can break it. But the sun bakes those deposits deeper every day. That's 300+ days of direct UV per year.

The damage timeline:

• Weeks 1–4: Surface-level spots or haze. Still removable with the right approach.
• Months 2–6: Minerals bond aggressively. Standard cleaning won't touch them. You need acid-based solutions or professional compounds.
• Beyond 6 months: Etching begins. The minerals have physically altered the glass surface. No amount of cleaning restores it.

Once etching happens, the only fix is professional polishing or full window replacement. We've seen homeowners in Henderson spend thousands replacing windows that a $200 professional cleaning could have saved, if they'd caught it six months earlier.

That timeline is real. If your windows have visible buildup and you're not sure how long it's been there, a free assessment from a professional can tell you exactly where you stand before the damage gets permanent.

The biggest culprits behind stained windows

Sprinkler overspray

Number one cause. Period. Ground-floor windows near landscaping take a beating. Sprinkler heads drift out of alignment, and suddenly your living room windows are getting hit with mineral-heavy tap water three times a week. We see this constantly in Summerlin and Green Valley, where well-maintained yards have irrigation systems that are just slightly off-target.

If your sprinklers are hitting glass, every watering cycle is adding another layer of minerals. A scheduled professional cleaning stays ahead of that buildup so it never bonds. That's where a regular cleaning schedule pays for itself.

Construction runoff

Henderson and the southwest valley have been booming for years. New builds and remodels kick up concrete dust and stucco particles. When that debris mixes with water from rain or cleanup hoses, it creates a mineral-heavy slurry that sticks to glass and dries hard. Post-construction deposits bond faster than standard hard water stains, so if you've had work done recently, get your windows cleaned before the damage sets.

Monsoon season splash-back

July through September, monsoon storms dump heavy rain in short bursts. That water picks up minerals from roofing materials, stucco siding, and concrete as it sheets down your home's exterior. Homeowners think the rain will clean their windows. It does the opposite. After monsoon season, we see a spike in calls from people who waited too long.

Hose and pressure washer splash

Washing your car in the driveway. Hosing down the patio. Every splash of Las Vegas tap water that reaches your windows leaves minerals behind.

DIY removal: what works and what doesn't

If your stains are fresh (a few weeks old, light spotting) you can handle them yourself.

The vinegar method

Mix equal parts white vinegar and distilled water in a spray bottle. Spray the glass generously and let it sit for 10–15 minutes. The acid dissolves calcium carbonate bonds. Scrub with a clean microfiber cloth, then rinse.

The detail most guides skip: rinse with distilled water, not tap. If you rinse with Las Vegas tap water, you're depositing fresh minerals onto glass you just cleaned. A gallon of distilled water costs a dollar. Use it.

Baking soda paste

For spots vinegar won't budge, make a paste with baking soda and distilled water. Apply to the stain and scrub gently with a non-abrasive pad.

What to avoid

Steel wool and razor blades. Professionals use both daily with the right technique. Without experience, you're more likely to scratch tempered glass (which gouges easier than people think) than to remove the stain.

The honest limitation

Look, we just told you how to do this yourself. And for a fresh spot on a ground-floor window, vinegar and distilled water really do work. But in Las Vegas, the DIY window is narrow.

Our heat accelerates mineral bonding so fast that by the time most homeowners notice the buildup, vinegar isn't going to cut it. "Recent" in this climate means a few weeks. If you spray vinegar and the stain doesn't dissolve after two applications, you've moved past what DIY can handle. Scrubbing harder won't help. Stronger acids risk damaging frames and seals.

And DIY cleaning means rinsing with tap water. So every cleaning session leaves a little bit of new mineral behind. It's fighting 304 ppm water with 304 ppm water.

That's where professional cleaning with pure water changes the equation entirely.

When to call a professional

This is the section that saves you money. Catching hard water stains at the right time is the difference between a cleaning and a window replacement.

Your stains are more than a month old

In this climate, a month of sun exposure on mineral deposits starts the bonding that DIY can't reverse. Professional hard water removal uses specialized compounds and polishing that break mineral bonds without damaging glass. It's a separate service from standard window cleaning, priced differently, but a fraction of the cost of new windows.

You have multi-story windows

A second-story window with hard water stains isn't worth a ladder injury. Professional window cleaners carry insurance, use proper equipment, and do this daily.

You see rainbow or iridescent patterns

If your stains show rainbow-colored or iridescent patterns, that's etching. The minerals have physically altered the glass. Professional restoration, polishing with progressively finer compounds, can save a window that looks ruined. A free assessment takes 10 minutes and could save you thousands in glass replacement.

The stains keep coming back

"I cleaned them last month and they're already back." We hear this constantly. If your windows face sprinklers, construction, or monsoon runoff, stains will return unless you maintain a cleaning schedule that stays ahead of the buildup. Professional cleaning every 3–6 months keeps deposits from ever reaching the bonding stage. Think of it like oil changes. You don't wait for the engine to seize.

Why the water matters

Here's something worth understanding. Most window cleaners use tap water mixed with cleaning solutions. In a city like Phoenix or Denver, that works fine. In Las Vegas, at 304 ppm, tap water cleaning can leave trace minerals behind on your glass. You're fighting the problem with a diluted version of the problem.

We use a XERO Pure Water filtration system, a multi-stage deionization setup that strips every dissolved mineral from water before it touches your glass. Carbon filters and deionization resin pull out calcium, magnesium, and every other dissolved solid. What comes out reads 0 ppm. Zero. Pure water.

Why does that matter? Water with no dissolved minerals is hungry for contaminants. When it hits your glass, it attracts and absorbs the dirt and mineral deposits off the surface because it has none of its own. It pulls the problem off instead of adding to it.

The result: your windows air-dry perfectly clean. No squeegee marks. No wipe residue. No new mineral deposits. The glass dries spot-free on its own.

Think about that for a second. This entire article is about Las Vegas's 304 ppm water destroying your windows. We clean with 0 ppm water. We took the problem and removed it entirely. Not every window cleaning company uses this equipment. It's specialized and costs more to operate. But in a city with the hardest water in the country, it's the difference between cleaning your windows and actually solving the problem.

Preventing hard water stains before they start

The best prevention isn't a product you buy. It's a schedule you keep.

Regular professional cleaning

Window cleaning every 3–6 months with a pure water system keeps mineral buildup from ever bonding to your glass. Deposits never accumulate long enough to cause etching or permanent damage.

For homes with heavy sprinkler exposure or near active construction, every 3 months. Most other Las Vegas homes do well with twice a year.

Adjust your sprinklers

Walk your irrigation system and watch every head cycle. A sprinkler 10 degrees off-target might only clip the bottom corner of a window, but that's enough. Adjust heads, replace drifted ones, and consider drip irrigation for beds against the house. This costs nothing and eliminates the number one cause of hard water stains.

Dry splash zones

After washing your car or hosing down the patio, take 60 seconds to wipe any glass that caught overspray with a dry microfiber cloth. Minerals deposit when water evaporates. Remove the water first, no stain.

Post-monsoon cleaning

Schedule a professional cleaning after monsoon season ends in September. Those summer storms deposit more mineral-laden water on your windows in three months than the rest of the year combined. A post-monsoon cleaning with pure water clears all of it before the fall sun can bake it on.

Your windows are worth protecting

Hard water stains aren't cosmetic. Left alone, they become permanent damage. In Las Vegas, with 304 ppm water and relentless sun, the timeline from "I should clean that" to "that glass is etched" is shorter than most people expect.

If your windows have hard water buildup, we can help. Vegas Glow will assess the damage, tell you what's needed, and get your glass back to clear. We use XERO Pure Water on every job, so the cleaning itself doesn't restart the mineral cycle.

Get a free quote at vegasglowcleaning.com/quote or call us to schedule a hard water assessment. We serve the entire Las Vegas valley: Summerlin, Henderson, North Las Vegas, and everywhere in between.