Green Pool


New member
May 13, 2008
Fredericksburg, Va
I pulled the cover back on my pool Saturday to pea soup. Never had it this bad before. Off to the store to get 10 gallons of bleach. My CYA was low last fall and I read zero on my test so I assumed zero. Cranked the FC up to 10 and it started to clear up. This was Saturday evening. Sunday was hard to keep it going because it was raining cats and dogs. But two times I adjusted it up to 10. Monday it was a lot better but I was back to work. Monday night much better but very gray and could barely see the bottom of the pool. Adjusted it back up to 10 Monday night. Tuesday morning still at 10. Tuesday evening down to 5.5 but could easily see the bottom of the pool. Vacuumed the pool but not much down there mainly some brown dirt. Adjusted it back to 10. Will check before going to work 6:30am tomorrow but I won't be back home until 5. My question is how long do I keep this going? The pool is not crystal clear still slightly cloudy.

My filter is 6 PSI over so I left alone. Will back flush in the morning. Sunday when it was raining like a fool not thinking I back flushed a long time to get water level down. Should have gone to waste to keep filter dirty and cleaning all the dead algae up. That may be why it's taking a little longer to clear it up. I have a big filter compared to some friends' pools, I like oversize things sometimes.

My current readings-

17500 gallon pool
PH 7.4
ALK 70
FC 5.5 (just put in 1 gallon, 1 quart of 6% bleach so on it's way to 10)
CH 170

I have a SWG that's not working. On my way to make a post on that board

Never cranked up FC this high before. Pool store said impossible to get algae with SWG. Amazing those brown spots the pool store said must be stained plaster cleared right up! I learn something new everyday!


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
It sounds like you are making great progress.

You need some CYA, it should be between 60 and 80 with a SWG.

It can take up to a week for the pool to clear after the algae is all dead. Backwashing won't slow that down much, might even speed it up a little. Dirty filters filter out finer particles, but dead algae is large enough that a clean filter catches them just fine.

It sounds like your FC level held steady overnight. If so all the algae is dead and you just need to give the filter time to do it's work.