I want to try adding some target fish to my festae tank (150 gallon). My male is 10" or so and the female around 4.5". They are the only fish in the tank and the male is overly agressive. Some days its directed only to his reflection and the pair gets along great and other days hes harassing the female. What are the best target fish to add that will school and he can focus his attention on them? I was thinking silver dollars but i dont want such bulky fish and the bio load of large dollars. Just looking for something fast he can chase and wont break the bank if he gets one.