Green Algae, now cloudy

[Spensar]

That's good progression. It can take a while to get rid of the cloudiness so be patient. I was gone for 5 weeks this summer and the folks taking care of the pool lost control and I am told it went green by neighbours. It was at least shocked back to grey cloud by the time I was back. My pool is around 20,000 gallons too and it took about a week to clear up.

I kept the chlorine at shock levels with liquid chlorine (5%/10% whatever was cheap) and used up half a bucket of calcium chloride too. I backwashed the sand filter twice since the pressure was up by 5 psi when I got back, and rose that much again as it filtered out the dead algae. I've never seen the pressure rise that much before, or that much crud get cleaned from the sand filter before. The pump ran 24/7 too.

Even though my pool wasn't green, the chlorine was being eaten up much quicker than normal, so it was still fighting the bad stuff. If there is still algae around and you let the chlorine levels get too low or zero out for a while it will rebound pretty quickly on you.

Vacumming was very important to clean it up. After a night or day of non-use there was a lot of silt on the bottom of the pool that was vacummed to waste/drain several times. I forgot to change setting from filter to waste once, and a pure stream of grey gunk came out of the input.... that didn't speed things up since it had to settle again. I did hit a point where the chlorine usage was normal so I was just really dealing with the dead algae silt/powder that had to go down the drain. Quite a bit of water was used up doing this - I guess about 4 inches total over the week from a 32x16 pool.

While the water was a mess I only adjusted for PH once because it was really low. Otherwise, I left all other adjustments for after the water cleared up. I must confess a bit of frustration with how tough the cloudiness was, but finally I went out one morning and could clearly see the bottom (and remaining silt!).