Thanks. This forum is so full of knowledge that is freely shared, I don’t know why anyone could not be an expert in this industry with some practical application and time.
Did the 700K house Friday and Saturday. Pictures forthcoming. But…She has been using well water and Windex to spray outside windows for years. ALL windows water spotted. Way outta my league. I showed them the spotting, as they thought it would just wash off. What the heck. Let me experiment. Bronze wool…nothing. Blue pads (thanks WCS, bought a case)…nothing. CLR…2 minute soak…blue pad…some. Blue pot scrubber, thin grocery store stuff, hand held sanding block and BKF after rinsing CLR…much elbow grease…5 minutes of work per pane…SUCCESS, water spotting gone, except edges, which I laid into heavy. Only did 5 large panes, took about 30 minutes. Oh and all windows are tinted. Did not phase tint…interesting. Would estimate at least a grand to do all windows. They would never go for that. But it was a nice experiment for my first try at real water stain removal. 
