Ok I have a few questions for the setup I am doing. I have a 280gal tank that is plumbed to the basement sump. The total water volume is around 600 gal. I want to keep a few stingrays in the bottom and maybe an arowana. I dont know what else I can put in that wont pick on the rays but will swim in the middle of the tank. What do you all think will work? My next question is do you all run uv sterilizers on your systems? I dont want to spend the money on one if I dont need it.