Don't be surprised if those other fish you have in there start to drop off as dorado can be tireless bullies,at least in my experience.I have had them snatch food from the mouths of other fish and then have the nerve to chase them around afterward.Your dorado could reach a certain size and then become stunted and possibly live for a few years in that tank.
I was reading The Charcins and it said that it can last with healthy large peaceful fish as well. so far I've had him for about 4 weeks now and he dosnt seem to bother any of the other fish. Well I'm definitely going to do whatever i can to make things easier on him in the tank.