Deep end vinyl yellowish/greenish tan stain after opening???

[CATCH94]

OK...pool is open, water clear and beautiful, chemicals good... BUT stain in deep end??

When I opened the pool, the water was crystal clear, but gunk on the bottom... mostly, uhm....... ::ick!:: worms!! ale: with some leaves...not many as very few trees nearby. Ok, not a problem; have opened to worms every spring. Vacuumed it all out, got chemicals adjusted properly, but deep end "hopper" is stained. Huh??? This never happened before. Won't brush off (pool brush attached to pole). I haven't gotten myself bodily to the bottom yet to hand brush (water a bit cold for me yet! 78 still), so I cannot be sure. What is causing the stain? Left over "worm" material? Highly doubt metal issue as Mother Nature kindly refilled the pool for us over the winter (had to drain some out twice!!) Stain only covers the area where the worms were. Also there are 2 fist-sized spots in the shallow end (again where worms were). How do I clean this???

Currently:
FC: 4.0
CC: 0
AK: 90
pH: 7.2/7.4
CH: 150
CYA: 50 (left over from last year... high CYA at end of season...no longer using pucks)
Taylor K-2006 test kit

Also, my Nitro Wall Scrubber (only a week old) didn't seem to do anything with the "stain" although it cleans beautifully.

Suggestions? HELP!!!!

 

[duraleigh]

Elevate your chlorine levels for a week or so and my bet is the stains will disappear.

Prove that they are organic (which I think they are) by holding a tri-chlor puck (if you have one) against the stain for a minute.........if the stain lightens up, it's organic and your elevated chlorine should take care of it.