Review on 🐠 AQQA Aquarium Air Pump, 2 Air Outlets Oxygen Bubbles Pump - High Energy Saving Adjustable Air Flow Ultra-Quiet Pump, for Fish Tank Up to 300/600 Gallons by Cathy Donaldson

The thing is very quiet, it makes almost no noise except for a very slight hum; which you can only hear if you keep your head a few feet away. In fact, I hear the water bubbles more than the pump itself. The sound is much better from a "commercial" air pump. My only concern with this pump is that it may or may not expel the advertised amount of air, but that could just be from an air pump that expels almost twice as much air. However, I will not abandon the product because of my own paranoia.