tank mates not getting along

[George]

Originally Posted by isaac1

So i picked up a new addition for my tank today and for some reason my peacefull fish have turned extreamly aggressive towards there new mate witch is a powder blue tang my scopis and tomato are loseing it but theyve never had a problem before i have 1scopis 3 chromis 1 tomato 1 cleaner wrasse and my tomato has never been agressive nor my scopis untill i introduced my powder blue they are all housed in a90 gallon with 80 pounds of rock any ideas or insight on this behaviour

It's expected for the tomato clown and the scopas tang to react violently toward the poweder blue tang. Tomato is considered to be one of the most agressive clown, generally speaking. Scopas is pretty aggresive toward other tangs.
It's best to use some kind of acclimation box to acclimate new fish. The box can be built out of some acrylic or egg crate. Some people even use egg crate to divide their tanks to acclimate new fish. Some people say moving the rock around work for them. Not many people can/want to move their rock around.
Good luck.