Pure water window cleaning scrubs the outside of your glass with a brush on a long pole and rinses it with water that has had the minerals filtered out. The spots on a window are minerals that tap water leaves behind when it dries. Take the minerals out of the water first, and the glass dries clear on its own, with no squeegee and no towel. We call our setup the deionized magic wand, and it's how we clean outside glass.
Why tap water leaves spots on glass
The U.S. Geological Survey defines water hardness as the amount of dissolved calcium and magnesium in water. Water evaporates off a window. The minerals don't. They stay where each drop sat, and enough drops make a spotted pane. The USGS calls the same thing on dishes hard-water residue: harmless, and easy to see.
The local numbers show why this matters here. The Great Lakes Water Authority treats the water that Birmingham and the other member cities of the Southeastern Oakland County Water Authority buy. GLWA's 2025 tests at its Lake Huron plant, printed in the City of Southfield's 2025 water quality report, averaged 105 milligrams of total hardness and 112 milligrams of dissolved solids in every liter of tap water. The USGS calls anything from 61 to 120 milligrams per liter moderately hard.
So a window rinsed with a garden hose and left to dry gets a fresh layer of minerals every time. Wiping glass dry by hand removes the water before it can leave much behind. A pole can't wipe a second-story pane dry, though, so the water itself has to be clean.
How the water gets pure
Our rinse water goes through two stages before it reaches the pole. Reverse osmosis comes first, then a deionizing resin.
Reverse osmosis pushes water through a membrane that lets the water pass and holds the dissolved salts back. A University of Massachusetts Amherst extension guide puts its removal at 95 to 99 percent of total dissolved salts.
Deionization takes out what's left. The same UMass guide explains the chemistry. The resin carries fixed electric charges. As water runs through it, the resin holds on to the charged mineral particles, calcium and magnesium among them, and releases hydrogen and hydroxide ions in trade. Hydrogen and hydroxide combine to form water. The minerals stay behind in the resin, and what comes out the other side is water with the minerals gone.
Running reverse osmosis first means the membrane does the heavy work and the resin only has to catch the last few percent. UMass notes that deionized water gets more expensive to make as the salt content of the source water rises, which is why the two stages run in that order.
The pole and the brush
The water-fed pole is a long, light pole with a thin hose running up it to a brush at the top. Pure water comes out through the brush head. The brush scrubs the glass and the frame, the water carries off what the brush loosens, and a last rinse sheets down the pane from top to bottom.
Then the window is left wet. Nobody squeegees it and nobody towels it. With nothing dissolved in the rinse water, there's nothing to dry into spots, and the glass dries clear on its own. No soap goes on the glass either, so there's no soap film left behind to catch dust.
What pure water is good at
Height is the big one. The pole reaches second-story bedrooms, dormers and the glass over a walkout basement from the ground. A ladder goes up only where the pole can't get the angle, so ladders stay off your siding, your gutters and the beds along the foundation.
That fits the subdivisions in Novi and Northville Township, built up through the 1990s and 2000s with two-story entries, an arched window over the front door and tall glass across the back of the house. The pole reaches the outside of that glass from the driveway and the yard.
It also suits the dirt a Michigan year puts on glass. Road spray leaves a salt film on the lower panes in March, and pollen coats everything in April and May. Both rinse off with pure water and a brush. Sprinkler spotting in summer is a different problem, and it's covered below.
Where the pole stops
Pure water and a brush clean off dirt that's sitting on the glass. Deposits that have bonded to the glass need more. Here's how that sorts out:
What's on the glass | Pure water and the brush | What it takes |
|---|---|---|
Dust, pollen and cobwebs | Comes off | Nothing extra |
Winter road salt film | Comes off | Nothing extra |
Tree sap | Needs help | Each spot treated before the rinse |
Hard water deposits from sprinklers | Needs help | Acid-based restoration work, quoted separately |
Paint, labels and silicone on new windows | Needs help | |
Etched glass | Can't fix it | Replacing the pane, or living with the haze |
If sprinklers have been hitting the same panes for a few summers, our post on hard water spots on windows covers what comes off and what doesn't. If your glass is already etched, we'll tell you before we start.
Three more limits are worth knowing before you book.
Inside glass is cleaned by hand. A pole and a hose don't belong in your living room. Inside, we also take the screens out and wash them, and we vacuum and wipe the sills and tracks.
Some windows still need a ladder. A roofline, a deck or a planting bed can block the angle. We point those windows out when we quote.
Freezing weather ends the outside season. Below freezing, rinse water turns to ice on the glass, the siding and your walk. Outside window cleaning runs March through November, and inside work runs all year.
The first visit can also leave a drip or two. Past cleanings with soap leave residue packed into the edges of the frames. The first couple of pure water cleanings rinse it out, and until they do, a little can run onto the glass and show a day later. The finish gets better with each pass.
What to expect on the day
For outside work, you don't need to be home. Leave the gate open and an outdoor spigot working, and we'll handle the rest. For inside work, someone needs to let us in, and it helps to clear plants and breakables off the sills.
Everything that comes with a visit is listed on our residential window cleaning page. The towns we work in, from Northville out to Birmingham, are on the window cleaning service areas page.
Questions people ask
Does pure water window cleaning use soap?
No. The brush does the scrubbing and the pure water does the rinsing. Soap leaves a film that has to be squeegeed off, and a pole can't squeegee a second-story pane. Without soap, the rinse water carries the dirt away and dries clear, so nothing is left on the glass to catch new dust.
Why are there drips after my first pure water window cleaning?
The drips come from old soap residue packed into the frame edges by past cleanings. The first pure water rinse starts washing it out, and a little can run onto the glass and dry there a day later. Each cleaning flushes out more of it, so the finish gets better over the first couple of visits.
Can pure water take off hard water spots?
Pure water adds no new minerals, but it can't dissolve deposits that have already bonded to the glass. Sprinkler buildup needs acid-based restoration work, which we quote separately from a regular cleaning. Glass that has etched can't be cleaned back to clear. We'll tell you which one you have before any work starts.
Does a water-fed pole work in the winter?
Outside, no. Below freezing, the rinse water turns to ice on the glass, the siding and the walk, so we clean outside glass from March through November. Inside glass is cleaned by hand all year, and January and February are the easiest months to get on the schedule for inside work.
Get a quote
Send your address and a rough window count through Get a Free Quote. We'll price the outside, the inside or both, and point out any glass the pole can't reach.
