Quiet Air Pump Recommendations

I have found the Interpet Nano Aquamini Aquarium Air Pump to be quite literally silent in operation. The air bubbles themselves of course make a noise.  It won't fit Humpalongs criteria for enough bubbles but for an "aesthetic pump" it is superb. I have also used it to prevent films from forming on the water surface.


https://www.amazon.co.uk/gp/aw/d/B00IF9NW62/ref=mp_s_a_1_11?ie=UTF8&qid=1521789217&tag=hotelaccom-21&sr=8-11&keywords=silent+air+pump

I'd guess it might be enough for a nano ("for aquariums up to 25L"). There wouldn't be many fish in a tank that small so, filtration aside, you'd only need a very gently turnover at the surface... can't help thinking though that if they made the same design for a big tank it might not be so quiet...

I have about 5 big airpumps in storage, including my old 70s Whisper 1000, which still works. But they're just so noisy...