3 Things to Know About Sand Filter Size for a 20,000-Gallon Pool

A 24-inch sand filter is the standard and works fine It handles the flow and turnover rate for 20,000 gallons without issues, keeping water clear under normal use.

A 30-inch filter is optional, not necessary It gives slightly longer cycles between backwashes and more tolerance for heavy bather loads or debris, but the 24-inch is sufficient.

Going too small is the real mistake A 20-inch filter on a 20,000-gallon pool means constant backwashing and higher head loss, wasting time and electricity. Always match the filter to your pump’s flow rate.