i've been there had to remove one of well 3 fish that i had grown to love and return them for trade became much aggressive towards a 11" common plec that i had the one was a very nice jag that i had to put down because of the huge gashs she received in just one night of attacks the others i traded back at a later time including my common to buy some fancy plecs all my fish are juvies now but the future holds a big enough amazion biotope they can all get aong well together