5 Types of Water for Cleaning Windows

Cleaning windows looks simple enough, yet the type of water you use makes a bigger difference than any cloth or spray. Of all the types of water for cleaning windows, some dry spotless and some leave streaks no matter how carefully you work. If you have ever finished a pane and watched smears appear as it dried, the water itself is almost certainly the culprit.

Here is a plain-English look at the five types of water for cleaning windows, and which one actually leaves glass clear.

Tap water: convenient, but it leaves its mark

Most of us reach for tap water because it is right there. The trouble is that tap water carries dissolved minerals such as calcium and magnesium, especially in hard water areas. As the water dries, those minerals stay behind on the glass as cloudy spots and streaks.

Tap water is fine for a first rinse to shift loose dirt. For a properly clear finish, though, it works against you.

Distilled water: pure, but hard work

Distilled water is made by boiling water and condensing the steam, which leaves the minerals behind. Because it is so much purer than tap water, it dries with far fewer spots.

The catch is practicality. Distilling enough water to clean every window in a house takes serious time and energy. It is a handy option for a single mirror or an inside pane, not a whole home.

Deionised water: the specialist’s choice

Deionised water has been passed through filters that strip out the dissolved minerals, leaving water that is very close to completely pure. With nothing dissolved in it, there is nothing left behind when it dries, so the glass dries clear without any polishing.

Pure water also behaves a little like a magnet for dirt. Because it contains no minerals of its own, it actively lifts grime off the glass and holds it in the water, which is exactly what you want.

Purified water and the pure-water method

Purified water is the umbrella term for any water that has been filtered to remove impurities, including distilled and deionised water. This is what window cleaners mean when they talk about the pure-water, or reach-and-wash, method.

Your local Tidal cleaner works this way. They use water that has been filtered until virtually nothing is left in it, fed up a telescopic pole to a soft brush. The brush loosens the dirt, the pure water rinses it away, and the window is left to dry naturally to a streak-free finish. A few benefits worth knowing:

• No detergents or chemicals, just highly filtered water
• Frames and sills are cleaned as standard, not just the glass
• Upstairs windows are reached safely from the ground, with no ladders against your wall
• Glass dries naturally with no smears or polish marks

So which water is best for you?

For a quick DIY wipe-down, tap water and a good squeegee will do a passable job, and distilled water will improve a small area. But of the five types of water for cleaning windows, pure water is the clear winner, and it is what every local Tidal window cleaner uses on their round.

The easiest option is to let them handle it. Book online in about a minute and you will see an instant price for your postcode, with no contracts and nothing to pay upfront. Your local Tidal cleaner sends a text before every visit, cleans the glass, frames and sills with pure water, and you pay by card, Apple Pay or Google Pay only after the clean. If you are ever unhappy, the 48-hour re-clean guarantee means they will come back and put it right.