A Fish Tank at Work?

So due to my move having negative overlap I intend to keep my fish at work for hopefully not more than a few days, but possibly as long as a few weeks.  This has led me to consider keeping fish at work on a more permanent basis.  There are a couple of considerations here.  First, it would create more work for me.  Second, it might lead to getting less work done while at work, and that would be no good at all.  Anyways, there would be a couple of things to consider, including the size of the tank that I would want to keep, and freshwater vs saltwater.  I can’t imagine keeping larger than a 10 gallon tank in any case, but I could imagine keeping something as small as 3 gallons and possibly even smaller.  I really have no experience with freshwater, so I’m actually intimidated by freshwater.  During the move, my 30 gallon tank will transform into a 75 gallon tank and move into the common room.  I think I may want to have a smaller saltwater tank in my bedroom, for my own personal enjoyment.  So that will be at least 2 saltwater tanks to babysit, so either way it’s probably going to be a while before anything develops.

The short story is that I anticipate doing a small tank in addition to my to be 75 gallon reef tank.  Possibilities include a greenbanded goby nano reef (~10 gal, maybe even less), a red fin waspfish “reef” (~? gal), or freshwater.  Principal concerns for this tank will be 1) noise level and 2) energy efficiency.