hi there, i'm not a new comer to the aquarium hobby, and especially not to keeping the monster variety. I'm in the process of setting up a 120 gallon to move my violet goby, otherwise known as a dragon fish into, seeing as how he is now 19" in lentgh and in a 55 gallon at this time. I am going to be adding a silver arowana to the tank and would like some ideas on suitable tanke mates. I don't wish to overcrowd the tank, and i certainlly don't want to create a hostile environment for my fish. Any uncommon fish would be appreciated, as i have a pension for the unknown. Thanks for your time, hope to hear some great ideas soon.