Our Aquarium Air pumps are optimized for both power and quiet operation. Produced for us by a leading European Manufacturer, Aquael. These pumps are reliable, repairable and offer surprising power while operating at low temperatures. The range includes pumps that work well on both very small aquariums along with larger aquariums up to 300 gallons (using two pumps). The three larger models feature built-in very precise flow controls that allow each side to be adjusted separately for operating air diffusers, filters and animated air ornaments. These pumps have pressure ranges from 1.9 to 2.9 psi and will pump up to 3 ft deep or deeper depending on setup.