I had a yellow tang and a powder blue in a 55 gallon. This was years ago and they got along fine. I did not read alot then and had total faith in the lfs guy. He said it would be ok to have the fish in that tank. Shame on him. I am happy to say he is out of business. I had those fish for 4 years. When I moved they did not make it. I was so upset that it took 9 years to think of starting another tank. When I went to the fish store only one in town that isn;t a bigbox store, I told the guy what
i wanted and he told me he wouldn't sell me a tang unless I had a 6 foot tank. I told him I had had them before and he said maybe it could be done but thaat it would be like me staying in my room for the rest of my life. Put that way made me start looking for a larger tank. Not the Tang police, I'm just sayin