The how much bleach do you use thread got me thinking. Richard reported that with a CYA of 30-40 he's using an average of 1ppm FC daily, with a solar cover. I've seen many reports of 2ppm being a common loss, which is what I experience.
I was wondering if a product like-
http://www.smartpool.com/website/recwat ... arpill.htm
Would provide any FC protection above and beyond the CYA level? I have no idea what these chemicals are, or how they might impact water chemistry, nor how much they cost. Chances are for what they cost you might as well just add more bleach, but thought I'd throw this out for discussion.