I would imagine the hardest thing with a tank that size would be keeping up with the evaporation. I have a 5 gallon nano and I set up a top off system because it loses about 250-500 ml a day when its warm out, not to mention the heat the powerhead is adding to the tank.
You could certainly get set up easily by putting an aquaclear mini on the back to run carbon etc. It would also help provide flow to the tank.
A nano is pretty easy to set up and depending on what kind of lighting you have you will most likely be limited in what you can keep in there. They're still pretty fun to set up though
