Rearrange sprinkler systems so ‘ Tap Water’ does not wet windows. Tap water contains calcium and other hard minerals and will, over time, etch the exterior of the galss.
can this glass be restored to it’s original shine?
99.9% of the time the answer is yes!
Calcium salts from tap water can be removed through the proper use of restoration chemicals, applicators and techniques. Although, once in a great while, I’ve found these techniques and chemicals to be ineffective. In that case, the problem stain has actually changed the molecular structure of the glass, and glass refinishing or replacement may be needed.
So, if your sprinklers are wetting your windows… Rearrange them!