Doc
I don't work for anybody
Pomacanthus angelfish are very aggressive. They tend to fight when one has dominated the tank. They will not tolerate the presence of another one, especially if they are both juveniles as many of the coloration is so similar. The trick to do it is the rule of threes. If your tank is big enough (180 or larger), add the smallest one first. allow two months for that one to become adjusted to the tank, and then add the other two at the same time. Make sure both of the new angelfish are of the same size, but clearly larger than the established angelfish. He will allow the other two in since they are larger and the two new ones won't fight because neither will have established territory.
To enhance your chances, make three clear and determined areas of rock for the fish to inhabit. There is always a risk and some angels just will never get along. I have had awesome luck with holacathus and pomacanthus angelfish in the same tank and Redline took my advice and he has a great pair of angels in his tank now.
As for the fighting, yes and no. They did posture a bit but left each other alone since they were both added at the same time. Unfortunately, they both died of Ich about a month after getting them. I think the tank was just too small.
Certain angelfish get along better with others. The more passive ones will do really well together: emperor, blue-face, and majestic. worth looking at if your tank is big enough. I am adding an emperor and blue-face into my 210 asap. Hope this was helpful.
-Doc
