Came home to find my 17 year old purple tang dead. Not sure if my 17 year old yellow tang finally won, but he was bigger than him for the last few years and they did fight now and then. I actually had them both from the start. Bought them both when they were like 2 inches each. Now the yellow is fat and about 6 to 7 inches big now. Not sure if I can introduce another purple tang in the 120......... Thoughts?