Review on AQQA Aquarium Air Pump: 5W Dual Outlet Oxygen Pump with 2 Air Stones - Adjustable Air Valve for Quiet Bubbler Pump - Suitable for Up to 160 Gallon Fish Tanks by Satsuki Silva

I looked at other air pumps before ordering this one and it seems the issue that bothers most people is the sound. I use this for my hydroponic system and have Alexa turn it on and off every 2 hours and leave it on for 30 minutes. I have found that when the pump is turned on with no hoses connected, it makes a loud noise. However, after the hoses are attached, the volume decreases significantly. Without lowering the hoses into the water, the pump makes very little noise - the pads on the legs help with this. However, once you put the air stone on, the whole process gets louder (mainly due to the bubbles). If you use this for a lidded aquarium, you won't have any noise problems. I think the noise level should be expected no matter what pump you use. The main thing to know is that the noise is not excessive. It gets louder as you increase the pressure generated by the pump. I really like that you have two output options and the button to increase or decrease the pressure is a fantastic feature. I also love how it comes with hoses, valves to prevent water buildup and engine damage, and two airstones. Overall I think this is a good pump that does what you hope and expect it to do.