Saltwater no, but freshwater, I would love an aro in about a 150g tank. I have a 75g now. The nastiest fish I ever had was a 2' snakehead. That was a long time ago, but he once ate a red belly pacu that i thought would be fine in the tank. I can remember the pet store I bought it off of had a display tank with one in it. It might have been around 180g tank or something but I can remember this snakehead swimming along the top moving real slow, it almost looked like a mechanical monster or something. I don't really know how big it was but I can remember the guy told me that he would feed it rats! Nasty stuff.