I've got a pool with MAJOR stains that needs be opened by next Friday
The stains are all from over the winter (there were a butt load of leaves and pine needles in it because the cover wasn't put on until mid-November). My last day was Oct. 31 and though I had scooped leaves 2X/ week, I could see the 'tannin' stains starting. I checked with small pieces of tri-chlor to be sure that they would lift (and they did), so figured that I'd just have to shock the 'Bejesus' out of the pool this season to lift the all around stains.
OOPS! I was wrong
Even a kneehigh filled with cal-hypo barely lessens the stains- and the strange thing is that the slight help is where the kneehigh full of cal-hypo isn't sitting (the stain is 'full strength' where the stocking is touching the floor), but the surrounding area is lighter?
Setting a lemon slice on one of the stains also partially lifted the rust colored stain (in the spot I tested).
On what were obviously pine needle stains, in the hot tub, a gentle rubbing with a lime removed the stains, while cal hypo and tri-chlor did not work - though they did work on some other stains. I know pine needles are acidic - is it possible that their acidity breaks down the marcite finish and embeds both their "metal" stain and allows the tannin, from the other leaves to take hold in the 'weakened' marcite?
The stains on this pool are fairly universal, though 'splotchy', white in most of the floor, heavy 'light brown' in wide areas and really rust looking in a number of spots (looks like something ate into the plaster in ~ 10 spots - those areas are darker and look [I haven't gotten in the pool because it's only 55* ] more darkly stained than the rest of the floor/ walls.)
I know y'all want and need it so here are the specs and chem #s :
Cl > 20 ppm
CYA < 30
Temp: ~55*(I haven't adjusted too much because the heater will take it up to 80* by next Friday)
I appreciate any and all help