so i recently went to a pet store to pick up some feeders just to tease my red devil hes about.. 10 inchs big in a 90 gal set up.. alone cause he killed off all his tank mates.. anyways about my story lol i met this breeder he breeds a **** load of different fishes and he made me an offer for a jardini arowana.. my question is... is a 120 gal tank set up big enough? and are they that aggressive and im receiving the jardini at about 8inchs big btw its free : )