I kept one for several months in my 240 along with a powder blue, yellow and purple tang. The Achilles was the last one added and he held his own against the bigger powder blue. They are very delicate fish. They require pristine water, lots of nori, and plenty of room to swim. Finding a healthy specimen that is already eating in captivity is the key to success. I purchased mine from liveaquaria and he did very well. Unfortunately I had to get rid of all my livestock when we decided to build a new home.