How do I remove that white scale from my window glass?

Is your window double pane? If so the stain might be on the inside from moisture that dried up. If it is a single pane, time to replace with a more efficient glass or window.

Hi Judyguay,

I would try CLR. If that doesn't work you may have to replace the glass. Sounds like you didn't get good glass to begin with or else someone has previously sprayed the windows with a glass etching compound.

It might not be white scale from hard water . That's what I thought was the issue with the Windows in the house I was buying . I thought it was from the sprinkler system that had the water hit the kitchen Windows . When the building inspector came , she pointed out the Windows and told us the marks that looked like water drip stains were actually the windows ' gas that is put between the panes as a form of insulation , was leaking out . A sign that the Windows would need to be replaced .

We still haven't replaced them , after 3 year . They aren't drafty , but I guess they might not be as energy efficient ..

If you're sure it's on the exterior of the glass and not in between the panes you could try wetting them w/vinegar then scraping them with a razor blade.

I've used Cerama Bryte on my glass shower doors. It removes the soap residue and hard water stains. It would probably work on the windows, too.

First, take an equal amount of vinegar and water and mix them together in a spray bottle. White distilled vinegar will work best for this. Then, spray the solution on your windows and let it sit for around two to three minutes. Lastly, use a gentle cloth to wipe away the cleaning solution and avoid any streaks.