The tang police rise again. Typically and for the best interests of the fish, tangs require ALOT of swimming room. especially the blue one. Just figure you can't keep the tangs in there together forever.
When I watched my tangs when I had 3, I was amazed at how much tank room they really like. The Kole tang which is supposed to be ok in a 75g was the most active tang racing back and forth all day. When I watch my yellow tang now I am thanlful I didn't throw one in my 55g like I had wanted to but was stopped by people on this forum. For that I am grateful .