Hey Skill,
Just FYI, Marie (and WaterBear & ChemGeek & more- Thanks to you all!) have posted excellent details on those products, how they work, their compatibility with fiberglass, and the whole chelating/sequestering issue. You'll find tons of info by searching for Fiberglass Stains or those product names. I would post a link, but there are easily a dozen threads I've found invaluable. Best of luck tackling this before closing!