adjustable-flow-pond-pump The Aquascape AquaSurge® 2000-4000 Adjustable Flow Pond Pump is an energy-efficient, asynchronous, submersible pump made for continuous use in ponds, Pondless® Waterfalls, and other water feature applications. Asynchronous motor technology provides superior reliability, maximizes longevity, and reduced maintenance with a maximum flow rate of 3,947 gallons per hour.