My last 2 questions for the season

[Lemonhead]

I went in to brush the walls and bottom today and I noticed just one green spot the size of a dime on the floor. I got it with my toe and it disappeared. Could it be anything else besides algae ? . 2 weeks ago I had several spots that were the same thing. I never had green or cloudy water. Just the spots. I even tested water and had no cc’s. My water chemistry is all in ideal levels. Could it be something else besides algae ?
My last question is about closing. I read the sticky but I’m still unsure of chlorine level. I’m going to do a thorough brushing and vacuuming. Than raise the pool to slam level. Should I than cover it with the water at the slam level or wait for the fc to drop to normal range ? Thanks for all the help all season guys. Sadly the season is ending shortly

 

[CaptainCannonball]

Kind of sounds like bird poop

 

[Lemonhead]

Kind of sounds like bird poop

If this was a serious reply , thank you. I actually have bird poo on the sides/ledge of the pool often. It’s white colored.

 

[Mdragger88]

I cover pretty much @ slam level.
The only reason to let it lower to 50% of slam is if u plan to use polyquat (as high fc breaks it down).
the fc & the polyquat will last longer if you’re water is cold 60 or below & u stand a better chance of opening to a clear pool.
The largest factor is water temperature - you want it mid to lower 60’s or below when u close & when u open
I also peek & take a sample throughout the winter to be sure my chlorine is still existent.