QZQ Aquarium Air Pump, Quiet Fish Tank Air Pump with Dual Outlets, 3W/5W Powerful Adjustable Oxygen Pump with Accessories, Aquarium Bubbler Aerator for Fish Tank Up to 80 Gallon (3W)

This one is quite large but it's completely silent sitting on a towel. QZQ air pump (3W or 5W - I think I have 5) https://a.co/d/024r29EH If you just need a small one, nothing beats this Hygger nano air pump. It doesn't need to sit on anything. hygger Ultra Silent 1.5W Fish Bowl Aqaurium Mini Air Pump https://a.co/d/0fAahmi9 Tetra Whisper Quiets are still fairly loud IMO. I try to cradle any air pump in something soft like a microfiber towel. Just don't wrap it up because that could cause overheating.