I have a newish tank almost 8 months old and having an issue with aggression in the tank. My brown tang died and my scopas tang has been aggressive to all the fish since. The fox face and scribbled rabbitfish fox face stays in opposite corners of the tank with their spikes up and in their camouflage state. I feel like I have tried everything and I honestly don't want these two fish to die because they have been in the tank since almost the beginning. Is there anything I can possibly do? Also I would like to know more information about power heads and sump tanks and etc. because right now I have a normal hang on the side filtration.