I second that. Whatever your Cl level, it won't be maintained much past a couple days, with or without a cover. Count on that cover to make the pool safe, and to keep leaf debris, etc. out, but that's it.

Not needing a safety cover myself, I'll pull a leaf net over to catch the Fall Bounty. When the trees have finished I'll pull it off, dump it and replace, then go thru the closing rituals and let the net freeze into the ice.

And Upstate NY, at 1000' elevation gets plenty of ice too.

C.