What is pure water?
Tap water contains dissolved minerals such as calcium and magnesium. When it dries on glass, those minerals are left behind as spots and streaks. Pure-water systems filter tap water through stages such as reverse osmosis and de-ionising resin until almost nothing is left in it but water.
Because pure water has nothing dissolved in it, it actively draws dirt into itself, and when it dries it leaves nothing behind — no spots, no streaks, no residue.
How water-fed poles work
The purified water is pumped up a lightweight telescopic pole to a soft brush. The window cleaner scrubs the glass and frames to loosen the dirt, then rinses everything down with a gentle flow of pure water. The windows are left wet and simply dry clear.
Because the pole extends from the ground, first, second and even third-floor windows can be cleaned without ladders.
Why windows stay cleaner for longer
Traditional cleaning with washing-up liquid or detergent often leaves a thin film on the glass, and that film attracts dust and dirt. Pure-water cleaning uses no detergents at all, so there's nothing left behind to attract dirt — which is why windows cleaned this way usually stay looking good for longer.
Frames and sills included
A water-fed brush cleans the frames and sills at the same time as the glass, so the whole window looks clean — not just the middle of the pane. It also means windows above conservatories, porches and extensions can be reached without climbing on anything.