i went down to our local petco a couple days ago just to look around while my parents went and got groceries, while walking back to the fish section i saw something that amazed me. they had an 8 1/2" oscar or tiger cichlid, and what i thought was a red belly pirahna but was a red bellied pacu that is abut 9" any who i have them in a 55 gallon tank right know while i get the money to get a bigger tank. but i really want to get another fish that is colorful and that will be able to live confertable with the oscar and pacu. if push comes to shove i wish to get some kind of arowana. never owned one but always wanted to. and i need to know what is a good tank set up?