It is quite possible, however I do not recommend doing so. A saltwater tank along is difficult to take care of, due to the amount of time you have to spend watching over the water levels, let alone a 2 gallon tank. Take Ausie Fish's advice. Start out with a 55, to get the feel, 30 at the smallest, and work your way down. You will save much heartbreak by doing such. Not to mention, saltwater is VERY expensive. I had to get out of the hobby, when I could not afford to move my 5 gallon bow fowlr, to a reef. Maintence is difficult, and the fish are very delicate. Keeping just a saltwater fish only tank, is like taking care of a fully planted discus tank. If you can handle discus, give the saltwater a shot, otherwise, leave it for the experienced.