yellow tang be fine, in 75 by his self,,
the problem will be when you want to another fish he will mostly like be aggresive toward it,, tangs you want to add last, and if you get more than one , add them all at the same time. just make sure they get a good diet of greens,,nori on clip is what i do,, in there weekly diet and you do fine. i also feed my yellow tang, several different frozen foods during the week along with flakes with garlic.