so i have a 5 to 6 in clown knife, who is the second in command of my 90 gallon, i just purchased a 3 in arowana and he keeps eyein it up, ive fed him bloodworms and 4 prawns just to try and keep his appetite down.. i really dont want him to eat my first ever aro hes just growing out in the 90, the only option i have to make sure he doesnt even try would be to put him in my 50 to grow out, that requires moving my big juvie red bellie piranhas into a small qt tank i could set up for them for a month... should beokay right? only till my aro grows at least another inch