dominance hierarchy in the QT tank, what to do?

[stevenearlmcdonald]

I have four fish that I have been quarantining for about a month. 3 green chromis and 1 molly miller blenny. Everything has been fine for 3 weeks but yesterday I saw two of the chromis ganging up on the third one. Then this morning I found that the third guy had jumped through a tiny hole in the lid and died. The most aggressive chromis than was nipping at the other chromis so I put the guy getting picked on into a macro algae tank I have. I went from 4 fish quarantining to go into the display tank to two fish, an aggressive green chromis and a molly miller blenny.

what should I have done? separate the quarantine tank? keep them separated and only put one in the display tank? which one, the dominant one? (which might be good because the only fish in the display tank at the moment is an aggressive clown fish.

 

[vetteguy53081]

I have four fish that I have been quarantining for about a month. 3 green chromis and 1 molly miller blenny. Everything has been fine for 3 weeks but yesterday I saw two of the chromis ganging up on the third one. Then this morning I found that the third guy had jumped through a tiny hole in the lid and died. The most aggressive chromis than was nipping at the other chromis so I put the guy getting picked on into a macro algae tank I have. I went from 4 fish quarantining to go into the display tank to two fish, an aggressive green chromis and a molly miller blenny.

what should I have done? separate the quarantine tank? keep them separated and only put one in the display tank? which one, the dominant one? (which might be good because the only fish in the display tank at the moment is an aggressive clown fish.

Very typical of chromis and damsels who soon then turn on each other - Unfortunately

 

[MnFish1]

As far as QT - it's often to use a larger number of these types of fish (as compared to 2 or 3). Did you treat with medication?

 

[stevenearlmcdonald]

As far as QT - it's often to use a larger number of these types of fish (as compared to 2 or 3). Did you treat with medication?

I have a smaller tank 30g and I was going to do 3. I had two before that passed away this past year both were 9 years old. I was at the end of the copper treatment and water changing out the copper before prazipro treatment. They were fed and feeding well and all about the same size very small but one seemed to hit the switch and became super aggressive towards the others.

 

[Jay Hemdal]

Green chromis are troublesome - they school in the wild in large shoals, but they tend to fight in smaller groups. I always get them in groups of five or more, but I still see some fighting.