Once I close my pool for the winter, that's it for me. I only check to see if the water level's getting too high, then I siphon some off. Only once have I opened to any algae and that was last season because I opened very, very late.

I don't close until the water is at or close to 60 degrees. I then run the FC up to shock level and keep it there for a couple of days.

I then add a quart of Polyquat 60% and wait 48 hours.

I raise the FC up to shock level again and close.

That's it.