We've had an unseasonably cool August here in Indiana, and no one has used the pool for 6 weeks. With no warm weather in sight, I'm going to partially close the pool today. This just means I'll cover it, but keep it balanced and the pump going until we get closer to freezing. I use a mesh cover with a system that suspends it, so there is no interference with the pump. I've kept my CYA low this season, right at 30, so it's dropped below before. I noticed that I was having a hard time keeping the FC level up this week, so tested, and this would be why, as it's definitely <30 now. Since I'm covering it today, would raising the CYA back up to 30 have any benefit? There won't be much sunlight penetrating, but there will still be heat. The pool water is currently 73, which is about even with the air temperature.