i have my sohal in my tank with four other tangs, and my sohal was the first one in which i heard was a horrible idea but all my tangs swim around with each other all day long like a school, its very kool to watch, your sohal should only be aggressive for a day or two and then you should be fine. i dont have any issues at all with mine anymore, once i add a tang in there he will be aggressive towards it for only a day and then he is fine and i never see any aggression after that