We're in the Salt River Valley of AZ, east of Phoenix. Pool temp is 58 now. Don't use a cover, and just check pH & add a gallon of chlorine every week or so during winter. I have a fairly high CYA (160) so not too much drift. I've heard a rule of thumb for summer to run filter pump 1 hour for every 10 degrees of high temp...if this is somewhat accurate for summer, does it apply for winter too? I think I'm set to run 10pm to 4am now...is this overkill?

Thanks, KC