Adding a 3rd clown to my tank...bad/good idea?

[joe-ejs]

Hello. I have a 90GL tank that has housed a pair of Clowns for the last few years. I inherited some fish including one clownfish. It is currently in a QT tank. Will there be an issue adding another Clown to my tank that has the other two Clowns within it?

 

[exnisstech]

I would expect the pair to attack it.