A 2 by 2 by 6 foot tank is about a 180 gallon.
I have got a Black Arowana about the same size yours and I have been considering buying a second for my 360 gallon. Your pictures make me want to pick up a the second 14 inch Black Arowana. I think I'm going to hold off until I up grade from a 360 to 450 gallon tank.
Great tank and nice arowanas!