I love tangs! They are some amazing fish! From my experience with them I can tell you that there's no non aggressive Tang out there but they eventually settle in well with each other. You are going to get the initial battle of who's boss for a couple of weeks, but they eventually will settle and even school together. I have a 300 gallon Fish only tank that I had to have because of my love for Tangs and Angels, and I can tell you that my Purple tang is the boss of that tank, and he makes sure to let every new comer know! Enough on that lol!! I think you could go for whatever Tang you would like to keep, just be mindful that the battles are going to happen and there's nothing you can do about that. Try to find them in the 3 to 4 inches range since it seems that size has the better chance or adapt to captive life, unless of course is a Tomini or any of the other smaller species, in that case I will go with 2 to 2 1/2.I strongly advise you to quarantine your tangs, they are prong to ick and the stress of the possible battles will weak their immune system and make them more susceptible to the disease. I use 40 gallon breeders tanks to quarantine mine, there's enough space for them to swim and be comfortable. If you have any questions on any particular species, put the names up, I'm sure someone here can tell you everything about them.
