From what I have been reading they only grow to 3 inches. Think I would want more than a 10 gallon for them though. Be nice to them and give them some space
IME of these fish that's nothing like the behaviour of them.
They move around loads I haven't seen a scrap of territorality at all in fact they stay together most of the time and they are certainly not as messy an eater as a puffer.
Just my experience I might add.