20k inground pool.
Since opening, the pool is completely green. I shocked the heck out of it, for days now. No change.
It has only about 3-4 ft of visibility.
I added 8 gallons of shock (12%), just yesterday. The day before, 4 gallons of bleach. 10 bags of powdered shock in the last week.
Ran filter 12 hour runs, then even 24, backwashing the sand filter every few hours or in the morning if I ran it overnight. Still, NO change. Chlorine feeder (in-line) is maxxed out.
I've got the Alkalinity correct, and the PH, and chrlorine levels are very high, STILL, no change.
I'm starting to think it's not the chlorine, and but the filter is NOT filtering the algae.
I read that dead algae is brown or grey, but this isn't happening. No matter how much shock I put it, the pool is still green. There doesn't seem to be algae growing on the walls, just in the water.
I moved here only 2.5 years ago and have no idea how old the sand filter is, or if the sand needs replacement. Should I replace the sand anyway for better filtration? I didn't have this problem in previous summers.
When I backwash, you can see a lot of green coming back out, but the water color, if anything, got WORSE by this morning (in the pool), after 8 gallons of shock, and running the filter for 24 hours (including at least 4-6 backwashes).
I'm at my wits end here. Never had a problem like this that wouldn't clear up in a week before.