I am new to freshwater fish and have just started. I have 5 platties: 3 candy cane and 2 coral blue (all males). My problem is that one of the blue platys is constantly picked on by one of the candy cane platties. He ends up swimming into one of the top corners of the tank and stays there while the candy can platy follows him and seems to pick at him. The blue one will turn around and pick back, but now he's always in the upper corner of the tank, even when the candy cane one leaves him alone. Any suggestions for what's going on and what I can do? Thanks!