Alkali. The bane of my existence. That stuff is so bad in my water (and soil) it's not even funny. I can't even wash my Taco in my own damn driveway without ruining the finish (even with an in-line filter). Unfortunately, as I live in a wind-prone area, my sprinklers get blown up onto the front windows of my house a lot (not to mention the now opaque that used to be see-through shower doors). After three years of swearing and fighting with the crap, I was about ready to just say screw it.
In wandering aimlessly about the interweb a while back, I came across this stuff. As with all 'wonder drugs', I had my doubts. Well, I just broke out the ladder today and gave it a shot. Much to my amazement, this crap actually does what it claims to. I didn't think that was still possible nowadays. It took about three hours to completely do two large windows, but for the first time since I moved in here, I finally have clear windows again.
And for the disclaimers- No, I'm not a paid spokesman (or in any way connected) for this product and yes, YMMV, but it worked for me. Better than I ever could have imagined in fact. Just throwing it out there-