I think an aquarium is a less than ideal grow chamber. You can use an upside-down aquarium as a clone dome though in a pinch, lol~

The material, rather than the size, is the issue. Something sturdy and lightproof is the best way to go, and a 'rubbermaid' or equivalent bin is much easier to work with, since you can cut holes in it for exhaust and modify the HECK outta the thing!