I have one I got about 3 months ago. I got it from a local guy that had it in his 90g, it was about 4 inches long and he said it had not grown much. I put him in my 300g reef with 3 other tangs and 2 sharks. He has doubled in size in those 3 months, i think he was cramped in the 90 with lots of rocks. My tank has only about 100lbs of rock so lots of swimming room for him and the sharks. He behaves great with the corals, sharks and other tangs. He will be going into my 600 in a few months. I would say they need at least a 220-240g as they swim back and forth all day. my .02c