What size pump should I get for my above-ground pool?

A 1 HP pump is right for most above-ground pools up to about 24 feet across. Anything bigger is usually overkill because above-ground pools are shallow with low plumbing resistance. A 1 HP pump turns over the water in 8-10 hours, while 1.5 HP can suck the liner inward, stress the filter, and waste electricity. Unless your pool is over 30 feet or you have a high-flow sand filter, stick with 1 HP.