Though I still stand by the advice that you can't go too big with a sand filter ------ I was just talking with Poconos, a former forum moderator who is more of a pool equipment guru than I am, and mentioned this thread. He agreed that you could use the bigger filter but also thought that the 24 inch one (300 lbs of sand) would actually do just fine on your size pool and would save you money. I have a Hayward filter but can't tell you specifics about their various models.