If the firefish are sexually mature, there will be a fight for dominance. (which you have already witnessed) I have never succesfully kept more than 2 firefish for any length of time becuase of this fighting. (many carpet surfers, as they junp from their aggressor)
I would recommend against it.
I have a pair of firefish that I've had together for 6 months in a 15g reef. I'm upgrading to a 40 and was wondering about adding more, I've heard if you have 2 that havent killed each other to DEFINITELY not add any more as they are a pair. mine had some spats and dominance issues, but now seem to be getting along fine. can I add more in the bigger tank or should I stay with just the two? any experiences?
