Could a clown knife, 2 parrots, a green sev, a festivum, 2 angels, and a fire eel live in a 6' x 1.5'(or 20inches, not sure) x 1.5' (again, maybe 20 inches)
So it is big enough. I haven't bought the tank yet, but i'm going to pick up the knife on the 21st. He's going in a 36 x 18 x 15 growout tank.
P.S. i'm pretty sure the width and height are 20 inches not 18
Forget about the growout and just throw him staright into the bigger tank. He'd be MUCH happier. In no time he is going to require a much larger tank. Keep in mind these fish grow 3ft.