are you seeling that flagtail. i have one that is overly aggressive. it killed my blood parrot, 2 peacock bass, another flagtail, and my juruense catfish. i'm afraid it's gonna kill my uaru's next. i tried to contain him but i think he scratched both of his eye trying to get out. i think he is blind now, but some how he still manage to kill the blood parrot and is still going after other fish. it's insane. i haven't had a fish this aggressive since my jardini. and my flagtail is only 4". the other fish he killed were the same size and some a bit bigger.