well the thing is both of tem are in a 75 gallon right now and its ok for the most pert except for when they bump into each other then the battle starts and sometimes the devil just wants to pick a fight with the butti and the butti just try's to avoid the attacks for the most part untill he get po'ed and then he puts the devil's entire face in his mouth. But they are still young fish the butti is 9'' and the devil is 8''. The devil has been in there just under a week and i was told some bad info by the lfs and i was an idiot and impulse bought the buti before knowing too much and he just got put in there las nite. and it made the tank look a whole lot smaller real fast so i think im gonna upgrade to the 125