I have light staining over the entire pool plaster which gives the blue pool plaster a yellowish tinge. I had some dark small 1/2" stains that I removed with ascorbic acid tablets. This actually cleared a yellowish tinge area around the dark stain, too, for about a foot. I read about Metal Magic on here, and am wondering if people here think I should try Metal Magic to remove the yellowish tinge. I was going to do an ascorbic acid treatment, but it would seem Metal Magic would be much easier.