+1 - I had 2 juvies in their own tank, one grew bigger than the other and started terrorising the smaller one so put bigger one in community tank and it terrorised fish in there - killed my huge female swordtail and then started on discus when swordtail died. She got thrown into my monster tank and seems to be happy there - certainly not picking on anything (as they'll bite back, hehe)
The first time I tried to catch her was impossible, so I tried a calm and quiet method and snapped her up first pop - could have been just lucky though.
The smaller juvie is now in the community tank and no issues with the other fish - clearly has a quieter personality and knows how to play nice :thup: