ok i put my puffer fish and my baby oscar(maybe the size of two ping pong balls....into a 15gl tank......they stayed away from each other....but im worried that if i leave the room...one will attack the other.....cuz it looks like the oscar is afriad of the puffer....but the puffer wont attack the oscar cuz hes bigger then him.....but not that much bigger.....so whats going on and what do u think...??