I have a Fluval C4 and it’s tolerable quiet and then loud and then back to quiet and so on. I know AquaClears use the same motor and impeller as the Fluval c-series. So I don’t see how the AquaClears are quieter than the Fluval C-series filters. For anyone who has an AquaClear is it silent right out of the box and years later? Also, how does the sound of it compare to the Marineland Penguin series?