Trouble balancing chlorine/sequestrant - stains keep reappearing - help!

[KatyO]

I posted a week or two ago about some staining upon opening of the pool. Did a SLAM, got the pool gorgeously clean, lowered chlorine, added polyquat, did a big AA treatment and followed up with Jacks Blue Magic. It was awesome to watch it get clearer literally by the minute. Things looked AMAZING for a bit...but as the AA has all been eaten up and I've been raising the chlorine - stains are coming back. So we did another round of AA and MORE Jacks. Boom - all clear - but then reappearing as I raise chlorine.

I can't keep pouring Jacks by the bottleful in every week. HELP.

Current test results -

CYA 80 - I know this is high but the pool gets FULL sun for 12 hours a day in the summer, last year when it was lower we blasted thru chlorine like crazy because of sun...so we purposefully raised it...now I'm wondering if this is part of the problem because our FC needs to be at least 6 according to the pool calculator
FC - 6 - as soon as it was in the desired range stains came back
CC - 0
TA - 60
pH - 7.5

Options I have thought of:
1. Drain water and refill to lower CYA so that our desired FC range is lower - would this help keep staining from reappearing with chlorine?
2. Keep CYA where it is but keep FC below the recommended range and add polyquat regularly?

Either of these valid? Any better suggestions? I can't keep doing what I'm doing - it is way too expensive for a pool this size!

 

[aeh0603]

I can't tell you what the best option is since I am getting ready to do my first AA Treatment at the moment, but I can tell you that draining and replacing some water can help for an additional reason. Assuming your fill water does not contain metals, draining some water from your pool will also reduce the metal ion concentration in your pool water. If there is less metal in the water it is less likely to redeposit as a stain.

I have also read that keeping your pH closer to 7.2 can help keep the metal in solution, but unfortunately unless you find a way to remove metal from the water you will probably have to keep adding a sequestrant to keep the metal from redepositing.

Hopefully someone with more experience will be by soon to help you out. Good luck!

 

[pooldv]

That is the annoying vicious cycle with metals. It has to either be captured with sequestrant or in stains or in the water turning it green or brown. Or removed from the water altogether.

Is the stain from copper or iron?
Do you know the source?
The cheapest and easiest option is to leave the stains alone and swim in the pool.
It is possible to try to cause the metal to precipitate into the water and then try to filter enough out to get the level low enough so it won't stain.
You could drain and refill if the metal source isn't in your fill water, or get some trucked in water
You could reverse osmosis filter the metal out of the water.
Then capture rain water to refill the evaporation and splash out.