Hello, I have a Yellow-tail Acei cihlid (about 3in long) in a 50 gallon tank with 7 other cichlids and a pleco. I've had my tank for about 7 months now. I recently noticed that my Acei cichlid has been flashing and rubbing on rocks and decor. He also occasionally swims erratically around the tank, and I noticed that my pleco has been trying to clean him. None of the other fish seem to be showing this kind of behavior. I was reading about the different fish diseases that he may have, but none of them seem to match the description. He doesn't have any loss in appetite or cloudy eyes, and he is not being bullied by the other cichlids. Anyone know what this could be?