I have a new Aqueon Quiet Flow 20, it is very quiet. I think it was louder in the very beginning but is now so quiet that I can only barely hear the motor if I am in front of the tank. I put some kind of bubble wrap between filter and tank, I felt there was some vibration.
My oroginal 30 is silent. The new
One varies but is never "quiet". My fluval is as if its not there. Flow set to 30%