That's a big fish for a 70 gallon tank, even liveaquaria says a minumum of a 180g display, it gets a full foot long!hi all, i've always wanted a hippo tang. In the past, many many years ago, I tried one or two that died. I will say that back then i didn't have the best stability. 20 years later have way better success rates with most live stock. I wonder if I can add a hippo tang now. My fear is that i think they are super fragile in the smaller sizes. I have a red sea reefer 350, so 70 gallon display mixed reef. The only bullies in my tank that might not like new additions are a salfin and coral beauty. although the salfin keeps the coral beauty in check. The last fish i added was a fairy wrasse and to my surprise, the only one to chase it around for the first few days was my starry night blenny.
But if you're actually going to rehome it when it gets to 6" or 8"...maybe? It might keep up with the sailfin, but I wouldn't count the wrasse addition like a tang, the sailfin will know the difference. If it were me...I wouldn't do it, I'd get a tomini or a kole, though!