I have well water that contains copper and iron - 0.1ppm and 0.3ppm, respectively, at last measurement. As a result, I have a light amount of metal staining in my fiberglass pool. At the beginning of the season I wanted to tackle it with an ascorbic acid treatment. I added the polyquat 60 and put in 1/2 lb of ascorbic acid on 5/20/13 and 14 oz of Metal Free. Didn't realize at the time the Metal Free was useless. When I started slowly adding chlorine, I got slightly green, very cloudy water. On 5/24 I added 1 qt of HTH Metal Control - results for the pool at that time were pH 7.2, FC 1.5ppm, CC 2 ppm. I know I was not supposed to shock for at least 2 weeks but the pool looked gross, and I couldn't take it anymore and added 2 gallons of 10% liquid chlorine. The water cleared but now I can't get the CC down to zero. Since 5/28 I have been following the TFP shock process (as opposed to 'breakpoint chlorination') and I cannot get the CC below 2 ppm. I am testing and adding chlorine several times a day. The CC has gone as high as 4ppm, but not lower than 2ppm. The water is beautifully clear. Unfortunately, all staining has returned and then some - I now have staining on my side walls which is a new. Current test results...
FC 0.5 ppm
CC 2 ppm
CYA -not showing as readable with test kit - but it was at 35ppm prior to the acid treatment
TA 125 ppm
CH 350 ppm
I am slowly resigning to the fact I may have to just live with the staining. But what do I do about the CC? I only have an 8500 gallon pool - so dumping it is starting to seem like the best option.