Colder weather can destroy an above-ground pool if you don't prepare it properly. Freezing temperatures cause water to expand, potentially cracking pipes, damaging filters, and tearing pool liners.

Q. I am a winter resident in Ft. Myers, Fla., and live the rest of the year in Massachusetts, where I have a vinyl 20-by-40-foot in-ground swimming pool. Last spring when I removed the cover, I ...