"This product is like magic! It removed the water spots (well water- not sure if it's water or salt from softener) from my quartz counter tops and my shower doors. I didn't think anything would ever get it off the shower doors (I've tried a lot of other products) but this worked great without a lot of hand hurting scrubbing. I put it on, let it sit for about 10 minutes and then barely had to scrub to get spots of the shower door."