have you ever seen a 3 to 4 inch fish in such a small tank??? Close your eyes and imagine yourself in a 4' x 4' room and walk around. That will basically feel how the fish will. They are open water swimmers and need alot of swimming room. My personnel opinion, I wouldn't even put a tang in anything under a 90 gallon. Not trying to sound mean but it is just way to small to be housed long term for. Now if it was a Q/T, then it would possibly be alright for a few short weeks. But If you do not have a bigger tank atleast cycling right now then I would not do it. Just my .02