Published in: Shop Circulation Pump 500 GPH Buy on Amazon Simulates natural river and reef currents by continuously circulating water Easy-lock suction cup makes installation, adjustments and removal simple Energy efficient motor increases water movement with less power Ideal for both freshwater or saltwater applications Directional water flow positioning with the ball and socket connection point 500 Gallons Per Hour (GPH); Recommended for 20-40 gallon aquariums