above is interesting and helpful
amp numbers? I wondered what they are, now tis clear.
electric bill? was not sure my calc was correct, now tis correct; nice to know
circulation? is nice to know that no circulation for a time with periodic cleanups is Ok
thank you
CAVEAT -- all of the below is written as a first time pool owner as of June (of a very old pool), so seek actual expert advise instead of anything I say!
The key is that low 40s water temperature that you mentioned -- keep in mind that many pools are closed up and covered for the winter, with no circulation and no chemicals. My understanding from these forums is that 60 degrees F is kind of the magic number. Our pool water is also in the low 40s, with many daytime temperatures up into the 50s and 60s. After some big storms dumped piles of leaves all at once in the pool that the pressure-side cleaner wasn't able to handle, between rain, dark, travel, and lack of the proper tool to get them out (an open mesh deep bag leaf rake to the rescue!), I had just shut off the circulation completely for about 2 weeks.
Once I got the right leaf rake and scooped out the big stuff, I fired up the pump let the cleaner go back to work again, it pulled the remaining debris and a lot of fine dirt out and the pool now looks ready to swim...if the water were 40 degrees warmer. Even leaving junk in the pool for a couple weeks and not doing more than dumping a gallon of chlorine in before we left, I saw no sign of algae.
My conclusion is that in the depths of winter running the pump for just a few hours a couple times a week is sufficient, especially if combined with some semblance of chemical management. That means I can run it on the weekend when I'm around to monitor and deal with emptying baskets and such in daylight. As the water temp climbs into the 50s I will put it back on a schedule and prepare for full attention. I also won't freak out about *trying* to get the December leaves out the instant they fall like I did this year; I'll just shut off the timer and scoop them out when I can. That wouldn't be true in areas where most of the leaves fall into warmer water in earlier months...
As always, YMMV!