NP-306 Submersible Pump The AQUATOP NP-306 fully submersible pump is powerful, yet quiet, and designed for very low energy consumption. Capable of moving 496 gallons per hour, the NP-306 is suitable for both fresh and saltwater aquarium use and is an excellent choice for water gardens or ponds. This versatile pump offers flow control and comes equipped with numerous multipurpose fittings for use as a powerhead or circulation pump.