Review on AQUANEAT Aquarium Air Pump 300GPH: Powerful Hydroponic Aerator Pump for Up to 200 Gallon Fish Tank – Oxygen Bubbler Included! by Sarah Abarca

Absolutely quiet even at the highest level, no rattling or wobbling. The adjustment knob is a little touchy, but it's not critical. Can be operated for smaller tanks or tanks. Works great, I'll probably get more soon. I personally think this is the most reliable air pump I have ever bought and the price made it even better, 5 stars. Update - my pump is still working great, I'm buying a second one today and will be getting another one in the future! I did notice that it can be a bit loud on the highest settings, but it's so well weighted that a slight adjustment on my stand eliminated most of the noise. Still much quieter than most air pumps of the same size and power.