I have a blue gourami, about 4-5 inches. He can be quite nasty and has been bullying fish in my 55 gallon tank. He only bothers other fish in close size to him, not smaller ones like the danios. I recently removed him from the tank, hoping that maybe re-introducing him after adding new fish might lessen his bullying. Will this work? What can be done to stop him from being an a@#hole?