This is a follow up to my post. I lowered the ph to about 7 with muriatic acid, crushed vitamin C pills in the food processor, sprinkled the dust around the pool, and as soon as the metals started to lift, added a quart of Conquest which I got from the local pool store. Stains disappeared, and have stayed off for the past 13 days. July 4th party was great - weather was hot and humid and everyone enjoyed the sparkling pool. I have been monitoring the water carefully, maintaining ph level low (7.2 on average), and adding polyquat every 4 days.

Chlorine levels are still low, lower than the best guess chart suggests for my CYA level. I am planning on raising chlorine levels to 5 ppm starting tomorrow, I hope metals will not be released. Oh - and the culator bag is showing an orangy color, so I guess it has been trapping the iron. Hope this post helps someone.