11 days of SLAM and still green - what am I missing?

[Bperry]

Update on FC levels for today
10pm - added enough to bring to 20ppm
1am - 20 ppm
7 am - 20 ppm
12:30 - 20 ppm
3:30 - 16 ppm
My pool is shaded up until about noon so now I feel like my CYA really is 40 and I’m losing the extra chlorine to the sun.
It looks like an algae bloom but it doesn’t seem to be acting like an algae bloom.

Losing 4ppm in three hours sounds like algae.

 

[Jpmcc]

Losing 4ppm in three hours sounds like algae.

Right - except I didn’t lose any at all between 10pm and noon the next day.

 

[crooks4hire]

Empty/Refill is on the scale of $300-$500 for me depending if I can get the water dept to give me a break on the sewer charge for filling (not likely as the waste water from the current pool has to go somewhere lol).

 

[crooks4hire]

I’m a couple days behind your progress. My green is nearly gone this afternoon. Still have 0.5-1ppm CC, so we’re killing something; but it feels like a weeklong plateau of blue/green murk just broke for me. Looks like it broke with cooler weather.

I did notice my CYA test creeped up a bit when I read about testing at room temp (my water was 65degF). My CYA is 60 and not 50. It’s barely above 50 instead of barely below it when read at 75+degF.

 

[Bperry]

Right - except I didn’t lose any at all between 10pm and noon the next day.

That good. It indictates maybe that there isnt anything organic consuming chlorine and all thats left is UV. Might be time to raise the CYA if you are confident its clean. If it isnt clear yet, itd be good to keep filtering as-is though.

 

[Deb04]

I'm going to let the experts weigh in here, but it kind of sounds like you had ammonia for the first few days of your slam. Doesn't fix where you are now, but it would mean that the actual killing of the algae didn't start until your CYA stopped disappearing. Maybe that will help with answering why this is taking so long.