5 Things to Know About Pump Flow Rate for a 20,000-Gallon Pool

Aim for 40 to 50 GPM That range is based on the standard rule of turning over the entire pool volume once every 8 hours. 20,000 gallons divided by 8 hours equals about 42 GPM.

Faster turnover needs higher GPM If you want a 6-hour turnover for heavy use or hot climates, you need about 56 GPM. Most residential pools are fine with 40–50 GPM.

Don’t oversize your pump A pump that’s way oversized wastes electricity and can stress your filter. Stick to the recommended flow range.

A variable-speed pump is worth the cost It lets you dial in the exact flow you need, saving energy and giving you more control.

Base your choice on turnover time Calculate your pool’s volume and decide on a turnover time (usually 8 hours) to find the right GPM. This avoids guesswork.