My three tangs are the Powder Blue, Atlantic Blue, and Kole Eye. They live peaceably in my 225 gallon. When they were small, you can see them sharing a piece of floating seaweed - like a water ballet. Now, the Atlantic Blue is 8" long, Kole and Powder Blue stayed around 5 inches. The Atlantic Blue and Kole have a very similar body shape but even with the very different color, the Atlantic Blue will chase the Kole. Not too bad as there is no torn fins or cuts... Just my own opionion though, it is not very nice to see an 8" fish swimming in my cramped tank. I would not recommend the larger tangs as they do grow to their full potential.