Sorry bro. But the dorado will mangle your bass in a short period time, once he has established dominancy there is no turning back. He grows as fast or even faster than your cichla. It doesn't matter what you do, he will stress, terrorize and eventually kill your bass in do time. I have lost MANY fish including cichla to dorados. I have a solitary dorado tank also, and it started with 7 dorados 3 years ago. Now at 27" strong about the only fish I see contending with him "maybe" would be a Hoplias (wolfish) other than that FORGET IT. Dorado are definately evil, aggressive and bogarding-type fish you take a Big gamble trying to mix it with anything... Even plecos catch the wrath. But it's not impossible for it to be done... Just HELLA HARD. HELLA MONEY. and HELLA PATIENCE.