Shoot for 1,500 to 2,500 GPH.

Depends on your pool size, but for most 1.5-inch hose filter systems on above-ground pools, that’s the sweet spot.

Go lower and the water doesn’t turn over enough – algae gets a head start. Go much higher and you risk blowing out the hose connections or starving the pump because the friction loss in a 1.5-inch hose is real. Most stock above-ground pumps in that hose size land around 1,000-1,500 GPH, which is fine for smaller pools (under 15ft). For a 20ft or bigger, you want the higher end of that range.

Don’t overthink it. Match the pump’s rated flow to your pool’s gallonage so you get one full turnover in about 8 hours. A simple online pool volume calculator does the math in ten seconds.