Originally Posted by Lindwurmx

Also got one more method to add on.

I haven't tried this method before and have not much experience in comming aros but read this article before.

Because your silver was the first aro into your tank and has been there before the other two it has claimed that as it's 'territory' hence aggression towards the newly introduced aros.

Same for the latter addition of your new black.

What some bros have tried is to bag out all your aros into separate bags and then later reintroduce them into the tank at the same time. This kindda makes them think that its a new space and because all of the go in the same time hopefully they won't fight for space.