Putting a small yellow tang in a small tank could be a good thing especially if you are married.
About three years ago, I put one in my 30 gallon cube. So when it got to about 3.5", I told the
commander-in-chief (my wife) the tang is getting too big for the tank and we have to trade or sell
it. My wife, who fell in love with the tang, told me to get a bigger tank instead. I am now in the
process of plumbing my new 120 gallon.