These guys are a very challenging fish to keep. Most times, they break down with a bacterial infection that covers their entire body and slowly eats away at them - regardless of their health at the time. I have seen very healthy Atlantic Blue tangs eating like pigs and yet still break down with this. The worst is when you get them as a semi-adult or adult. You have the best chance with these guys as a very young juvenile in a tank with non-aggressive fish, so that the blue tang can establish its dominance. I truly believe that this is a tang that does so much better in schools. If you were to go to a public aquarium that keeps this acanthurus, you will see that they keep several Atlantic blues in one aquarium, and the Atlantic blues always swim together.
Regardless, a tank with a lot of swimming room is a must, and this should be the first tang introduced so that it does not feel stressed by other tangs harassing it.