you will have more issues though with just two reds because thier agression is towards each other where if you have atleast three but better with 5 or more the aggression gets split more ways, Mr. Bubbles uses the entire 90G tank and I have had him for six years and have no plan of getting rid of him, he looks so nice because he never gets fin nips or tears so he has that perfect specimen look. and no he doesn't always yawn LOL! and yes he is spoiled he could be fine solo in a 55 for life but when I was upgrading I figured it would be best to go bigger as I know I will eventually have to replace him when he passes, will most likey raise a large tern or carbie after him.