Pool Closing Headache

[onebaddog]

Been using the BBB for 2 years, no problems until 2 weeks ago. had a bad storm blow thru. rain,wind, the usual. cleaned up leaves twigs & a ton of general junk that ends up in the pool. was running the usual numbers as follows.
Chlorine 6/8ppmFC ~ 0CC
PH @ 7.4
Alk @ 130
Cya @ 50/60
Started to cloud upafter the storm, still didn't have any CC when tested so i figured i would shock it. ran it up to 16ppm overnite with a loss of < 1ppm. after that i started getting a somewhat dark green almost brown deposits in the cracks of the liner on the bottom, vacumed up everything & overnite i had the same thing. held 6/8ppm fc & 0CC. i can't get rid of the stuff, i have tried to capture it with my fingers, but as soon as ya touch it it's gone, do not have to scrub it with the vacume, but you need to let it sit there for a second to pick it up. ran fresh numbers this morning after shocking it yesterday,
Chlorine ~ 16ppmFC & 0CC
Ph ~ 7.4
Alk ~ 130
Cya @ 50
I will check tonight after the sun get off of it & hold it @ 15/16ppm overnite & see what i have. Anyone have this same problem ? it's driving me nuts & i need to close. Any help would be GREATLY Appreciated, Thanks, Mike
Also the water is crystal clear, it's just the deposits on the bottom, Thanks again