I am starting this thread to discuss fish bullying. I have 5 balla sharks, 3 tiger barb and 2 angelfish in a 100 gallon tank. I recently re homed my red tail shark because I made the mistake of putting him in there with a couple of rainbow sharks also. He became a bully to all the fish even the ballas. Interesting thing is, since I removed them, now all of a sudden one of my tiger barbs became the new tank agressor. Oddly enough, he particualarly fights one of the other barbs. It has been an hour now of non stop chasing, and I have never had this problem out of them. I am going to separate them tonight. I understand I only have 3, I will add more soon, but I wanted to share this. Its interesting how it only started after I removed the redtail and two rainbow.