bjoe....i had dwarves as well, and actually gave mine to Rykna....in my opinion, you COULD do it in a 3, not many..but you could...but the problems are water quality in such a tiny tank..you have to keep on it so tightly...plus these guys MUST have live brine shrimp twice a day...which means hatching it yourself....which can be a great task if you have a lot already....if you are new to saltwater i definitely do not recommend them...if you are very expereinced in salt you could probably do it, but they are not the easiest horses to start with....i wouldnt do anything less than a 5 for them...water quality is always an issue in small tanks, even more so with these guys because you have to feed so heavily.