Return Pump

[grandprixsj]

I'm setting up a new 80 gallon tank in my living room, so it has to be dead silent, or I will be taking up residence on the couch. I built a beananimal overflow that is dead quiet, and set up a loop in my sump for my Turbo L2 Algae scrubber using a Sicce Syncra 2.0 pump that is also dead quiet. My problem is my return.


Originally I set it up using a Sicce Syncra 4.0 and 3/4" pvc. When I first turned it on, it was dead quite, but a day later it sounded like a power sander. So I re-plumbed it using 1" braided vinyl tubing. The gate valve is isolated from where I attached it to my cabinet with pieces of silicone tubing, and the pump itself is sitting on a piece of silicon mat. It is much quieter than before, but it still hums.


I have 2 questions:
1) Can anyone think of anything I can do to make the existing setup quieter? Perhaps my initial restrictive setup damaged the pump in some way, since it started out silent (for a day).
2) If I have to change out the pump, can anyone recommend a quieter model? I was thinking of the Tunze 1073.05...


Thanks in advance for the help...

 

[grandprixsj]

I forgot to mention that there is 4 feet of head between the pump and the return nozzle.