Blue Green Chromis Bullying

[Tateopotatoe]

I have one blue/green reef chromis picking on all of the others in my ten gallon nano. What should I do? I put up a mirror, but are there any other ways to prevent aggression? I also rearranged my scape. They will be going in a 50 gal soon, so the fix only needs to be temporary.

 

[Ol' Salty]

How many chromis do you have in your 10 g? Are they picking on other fish or just other chromis? They are normally a non aggressive fish that school together. But they might have to establish a pecking order. I am sure things will get better when you do go to the larger tank.

 

[Tahoe61]

Without more space the only temporary fix is removing the offender, but another one will likely takes the bullies place, it's the nature of the beast.

 

[RyanCSGO]

+1 to @Tahoe61
I have 3 and one was randomly chasing another throughout the day. at night they were fine. I removed the "bully" for a bout 3-4 days. during that time the 3rd one become a little more aggressive. I went ahead and put the other back into the original tank. nothing really changed in the end. maybe a very slight difference.

 

[Humblefish]

Chromis will often whittle themselves down to just one i.e. the winner. This problem only gets exacerbated when housed in a small tank.

 

[eatbreakfast]

Increased feeding and increased flow can help a little, but the bigger tank will help too. However if two pr up and start breeding it may be difficult for any others.