I followed the Ascorbic acid treatment post as best I could. Took the FC to 0 and added PolyQuat 60. I was so excited to see the stains disappear when I added the Ascorbic acid. The vinyl lining looked like new. It was beautiful. Then I added the sequestering agent (2 bottles of Jacks Magic Blue). Filtered for 24 hrs and then started slowly bringing the the FC from 0 slowly up to 0.5 then 1.0 then holding at 2.0. (PH was 7.2, TA was 50 and CYA is 30). I held it at this level for several days. It had been almost a week since the ascorbic acid treatment and all looked outstanding. I thought I was home free and was ready to celebrate.
Unfortunately I had to go out of town and left instructions to keep the FC at 2.0. When I returned, the stains had returned as much or worse than before I started. On the white steps and skimmer, the stain is a "Dirty Orange" and against the blue vinyl pool, it looks light green and covers about 75% of the pool.
Where did I go wrong??? How long does it take before the chance of re-staining goes away?? weeks??
I'm willing to start over, but want to ensure that it works this time. I suspect the sequestering agent. Was it the wrong one? Not enough? (it's very expensive). Or should I have kept the FC lower and used more PloyQuat 60. (I have no signs of algae). Or should I have waited longer and added more sequestering agent.
There are some smart people on this Forum and I an confident that you can straighten me out.
Thanks in advance for your help.