I have a school of 11 Black Skirt Tetras in a 40G tank. I have heard from a few here and other places that Angels can make good tankmates for these Tetras. My question is how many Angels can I add to my tank? I would be completely satisfied with the Tetras and, say, 3 Angels as I know the Angels can grow fairly large. Would 3 Angels be reasonable to add to my tank? Thanks in advance.