Water: Maximum flow through Flexible PVC Pipe April 22, 2026 22:56 Updated Approximate Maximum Flow Through Flex Pipe1.5" Flex Pipe: 2,200 GPH (gallons per hour) ≈ 8,327 liters per hour (LPH)2" Flex Pipe: 4,800 GPH ≈ 18,170 liters per hour (LPH)3" Flex Pipe: 11,500 GPH ≈ 43,532 liters per hour (LPH) Related articles Water: Volume in a Stream What size tubing should I use (1", 1.25", 1.5")? Recommended Pipe Size for Ultra Pumps Will chlorine affect the components of an Aquascape water feature? What is the best way to hide the face of the Waterfall Spillway?