Hi everyone - great board you have here. I'm hoping to get some help, I'm kind of at a loss here...
Using HTH test strips every few hours:
FC 10+++ (the pad on the strip is so dark it's almost black)
PH 8.4 (it was stabilized at 7.2 before I shocked though)
I have a 4-year-old 11,000 gallon above-ground pool and sand filter. I forget the brand of the filter but the handle has a W on it. The weather here has been overcast and cool, if that makes a difference.
Uncovered the pool on Sunday and the water was dark brown, worse than any other year so far. I got up on the ladder and started pulling out leaves. I think I got the bulk of them out but I can't see more than an inch into the water. Tested and adjusted PH, then started shocking.
Sunday afternoon I put 8 bags of calcium hypochloride 54% in, and by Sunday evening the water had improved to a murky dark green. Filter is running 24/7, pressure has remained constant at 4.
Sunday night I tested the water before bed and the FC was still off the charts so I went to bed and dreamt all night of a pool filled with dead algae by morning.
Monday morning went out to the pool at 6am and the water was still a murky dark green. FC was still off the charts but the shade of purple was ever so slightly lighter the night before. I added another 6 bags of shock and a gallon of algaecide. Spent most of the day on the ladder brushing the liner, pulling out some leaves and basically willing the algae to DIE.
By Monday evening the water had improved to a pea-soup green and I could see in about 2 inches deep. FC still off the charts at a very dark purple, almost black. Thinking more shock might speed up the process, I added another 6 bags and brushed the liner some more.
This morning I ran outside at 6am, thinking that HAD to work but the water has shown no improvement since yesterday... it's the exact same murky pea-soup green. The FC held overnight at a very dark purple on the test strip.
So since Sunday afternoon I've used 20 pounds of shock on an 11,000 gallon pool. Overkill? I know it's only been 36 hours but I don't remember it ever taking so long to show a marked improvement when I shocked. I live in the boonies and pool supply stores are a daytrip away so I'm relying on my test strips, my very basic knowledge of pool chemistry and the internet.
Any thoughts or advice? Thanks so much.