Followed the directions on this website for the AA treatment 2 weeks ago. FC was zero, ph 7.5, and added Polyquat before starting. Initial 1.75 lb dose in my 20,000 gallon pool removed most stains almost immediately, but I brushed and waited 24 hours to get the stubborn stains. Still some stains after that and ph at 7.2, so added another pound followed by more brushing and adding ProTeam Metal Magic. After another 24 hours only slight staining remained, ph at 6.8 and TA at 75. Raised TA and ph. Had to backwash the filter. Started adding bleach in small doses. After another 24 hours the water became totally milky, and I noticed I could stir up what appeared to be white powder on the steps. Is that the sequestered metal?
I added fiber to my sand filter to help clear the water and continued adding bleach slowly until the pool began to hold chlorine. After 3 more days the milkiness did not improve and the filter didn't seem to be trapping anything. A local pool shop suggested it was due to algae until I mentioned the white powder. They suggested turning off the pump (which had been running 24/7 all of this time) and letting the powder settle followed by vacuuming. After another 24 hours the milkiness did not settle, but I vacuumed anyway even though I couldn't see what I was vacuuming. After that the filter required another backwash. Another 24 hours later the milkiness had improved a little. I vacuumed and backwashed again. FC was holding at about 3 ppm by this time. CC about .5 ppm. Raised FC to 5 ppm. No improvement in the milkiness. Without vacuuming the filter didn't seem to be doing anything.
Finally after 2 weeks this morning I decided to shock the pool just in case it was all due to some kind of white powdery algae. No luck. I vacuumed again and backwashed again. My numbers now are:
FC = 12
CC < .5
ph = 7.3
TA = 95
Calcium = 280
CYA = 35
I have no idea what to do next short of emptying and refilling the pool. I've seen other posts about persistent milkiness after the AA treatment, but none of them seem to list the final resolution. Perhaps they emptied and refilled.