Thinking of a pool filter? What kind sand or cartridge.
Sand is the most popular because it’s less expensive. Cartridge filters on the other hand are more expensive however less maintenance. I like to use cartridge filters on our fiberglass inground pools because why would you purchase a maintenance free pool to have to backwash all the time. As well sand filters require the changing of sand every 3 years or so to operate efficiently.
Whatever filter you choose you want it to turn the whole body of water over in a 10 hr period.