my frogs live happily in a 5.5 gallon cycled and heated tank, they even try to breed. Definately make sure your tank is cycled properly, and from experience don't feed freeze dried anything, even pellets should be soaked as these guys get bloat very easily. The plants suggested above will work well for these little guys. As for telling gender, by the time PetSmart gets them they are old enough to tell, the males all have a small whiteish dot/bump like a pimple behind the front armpits, you may see this get swollen during breeding time.