FC, CC and Solar Covers

[Homebrewale]

Generally, CC over 0.5ppm indicates there could be a problem with algae. In my case, could it be the solar cover? We have not had the solar cover off the pool for two weeks due to both cool weather and travel. The pool has not been vacuumed during that time either and I can see a good number of leaves on the bottom of the pool. Last week, the FC was 9 ppm so I turned down the SWG from 30% to 25%. Still over 7 days, the FC went up to 12 ppm. Generally, you see falling FC if the CC is rising due to something like algae.

Should I make sure I pull back the solar cover for part of the day for ventilation and allow sunlight to hit the water? Also run the vacuum daily during this time since the organics load from the leaves is higher than would be during the summer.

 

[Newdude]

The CC outgassing is quick. Anytime i left my cover on too long I knew as soon as I pulled it back. It had a distinctive musty smell. But 45 seconds later it was gone. No 2 pools are the same of course, but for me it happened around the 7-9 day mark. I didn't need to pop the cover every day or even every few days.

since the organics load from the leaves is higher than would be during the summer

I have had enough leaves in my pool to make it officially be a tea, many many times. I have never seen any difference with fresh debris. Green leaves or freshly brown leaves are fine and won't matter. Debris that is already rotting and half broken down already is where it will start to eat your chlorine. The stuff that makes it under the cover and festers all winter needs to come out as soon as you open.

 

[Rancho Cost-a-Lotta]

You should brush down the sides of the pool even when it's covered. No vacuuming or brushing for two weeks under a cover is risky.

Just because your showing no CCs and your not pool's not consuming excessive amounts of chlorine doesn't mean there's not a problem brewing under you cover. I found algae growing on my walls after having it covered for a week during a recent heatwave. My tests didn't indicate any issues.