I shocked it, and cleaned it prior to closing. When I opened, water was crystal clear, and only found a couple of spots of algae on the walls that I'm positive was missed when I swept. It should have been dead because I shocked it, correct? Also, if it was live, I'd assume that I would have opened a pool that resembled a swamp? I live in Georgia, so winter temps range from higher 20's some nights, to 50's and low 60's for highs. I don't think the water temp ever gets below 45 or so. thanks.