OK, if I do the "winterize" thing, draining the lines and such (but not the antifreeze), and I don't cover it, does this mean I'll have to look at dirty water all winter? Do you keep chemicals in it, and how do you circulate? Keep in mind that I am in SC. I have no idea how cold to expect the water temp to go. Our typical winter weather is highs in the 40's to 50's, lows in the 30's, with a few cold snaps of 20's or even teens.