Unfortunately the product did not remove the water spots from my boats windshield. I followed the video instructions exactly, repeated the process 5 times in total without any progress. So don't get your Hope's up too high that this is the solution you've been hoping for. Many variables might be at play when using this to remove hard water spots off glass. Possibly the length of time the spots are on the glass might have been a reason why it was not a successful removal tool.