I had bought two black and white clown fish a few months ago. I made sure to buy one a little bigger than the other hoping that they would pair. They got along great for a month but now the larger one is always going after the smaller one during , even corners it so that it has no where to go. At night they sleep on opposite sides of tank but before would sleep together every night. Seems to have gotten worse when my flame angel died. Seems to be just a jerk clown fish. Lol even when I use a mag-float to clean the glass he tries going after it.