Well....an aquarium is certainly the last thing that comes to my mind when thinking of an Xbox....
BUT!!!!before you people deem the Xquarium a failure:
Ever thought of putting a modified Xbox in there and instead of water, use mineral oil to cool all the components???
People have been doing this to PCs for years and have gotten really good results in terms of noise and cooling performance! And how sweet would it be to have an Xbox that is actually close to being dead silent without having to invest in fancy, expensive cooling solutions?
Sure, you'd have to ditch the optical disc drive and figure out how to build in the HDD and controller ports, but if you have the skills to build an aquarium out of an Xbox, this shouldn't really be too much of a problem. Put some fancy LEDs in that sucker, lose the bright paintjobs (just go with black or some 2-colour combinations) and BAM instant nerdgasm.
Pardon me, If I'm exaggerating, but I would hate to see this project fail. And trust me, I'd pay real money for a working oil-cooled Xbox.
I don't want to make your work look bad, but you're wasting so much potential with it being just an aquarium. Also, the audience for an Xbox-themed aquarium is in my opinion, extremely limited. An oil-cooled, LED-modded, silent Xbox, on the other hand, sounds legitimately exciting!
Sorry for the incoherent ramblings, make what you want of it