I got my chocolate cichlid and synodontis catfish today. I love the chocolate cichlid. He is beautiful! But my oscar just seems to relentlessly chase him. (This is in a 125 gallon aquarium) I don't see any contact but if the chocolate swims anywhere close and the oscar notices him he chases him. I realize they need to establish a "pecking order" but when does it get serious? I really don't want him to kill the chocolate cichlid directly or either through stressing him out. Both fish are almost exactly the same size. The catfish is bigger but the oscar has shown a little aggression to him, too. If I had to trade one in, I would probably end up trading the oscar and keeping the chocolate and maybe adding a severum. Can you tell me when I need to be worried about the aggression? I don't want to overreact because I like my oscar, too. Thanks.