Things to Know
Hard Water and Glass
Florida is known for having hard water. What makes water “hard” is a high content of calcium and magnesium and other minerals dissolved in the water. When this hard water hits the glass and evaporates, it will leave behind mineral deposits. These deposits will show up as a chalky white coating on the glass. The longer this coating is left on the glass, the more etched into the glass it will become, making it more difficult to remove. If left on the glass long enough it may not be removable, especially if the glass has exposure to the hot sun.
Be sure to check your sprinkler heads. More than likely the reason you have hard water stains on your window is that your sprinkler heads are out of adjustment and spraying or misting your windows, leaving the hard water stains behind.
When you have your house pressure washed, be sure to have your exterior windows cleaned immediately after.
Most people when pressure washing mix chemicals with the water. If not properly washed off, the chemical spots left behind on the glass will be difficult to get out. If left on long enough, especially in the hot sun, the spots will etch in the glass. Once this happens you may not be able to remove the spots.