Variable Speed Pump VS 3050---gpm/rpm?

[mas985]

That was probably one of my formulas but the flow rate is fairly high for the RPM.

Running through my model I get about 107 GPM at 44 ft of head. 1500 RPM is half of that or about 53 GPM. Flow rate will always be proportional to RPM unless you have check valves, then it tends to drop faster with RPM. I assumed 35' runs and only one 2.5" suction line and one 2" return line plus typical equipment.