do you want an agressiv tank?? or a community tank? because my suggestion would be one(maybe 2) of them, and which one would depend on your answer, the 75 isn't as big as you think, these are big fish(except the lion), however the lion will eat anything it can fit in its mouth so you can't add much else, unless it is too big, which gratly reduces what you can get for in it because you do not want ot overstock by adding several large fish to your tank