I use the tunze9002 and it's not Loud at all. The fans are te loud part on the biocubes. It pulls dark hunky skimmate that has to be dumped weekly. I highly recommend it as I have the same exact tank. Airline modification and InTank cup is all you need
It's not that the Hydor is loud when skimming, it just makes a loud hum that reverberates throughout my tank. One other problem I am having with it is the amount of micro bubbles it puts in my tank.

