If it was me, I'd look for a used 29 or so. There are always great deals on my local reef club boards from people either upgrading or getting out of the hobby. I say 29, because it's a very popular size, an easy size to carry, and good dimensions for piling rock. And evaporation, temp changes, overheating etc. have a much smaller effect than on a Nano.
And you'll have room to buy SO many more
frags! Just sharing what I would steer a friend toward who wanted to get into the hobby.
