I would think 7 angels would be pushing it on a 50 but not out of the realm of possibility it would largely depend on filtration technique and tank configuration. Angels really do get big as adults. On the flip side 6 or 7 in a 90 with some of the afore mentioned Tetra's would be awesome. You'd still have room for cories or other tank cleaners/algea eaters. MY 70 will eventually have angels as a centerpeice with rams and some fillers here and there.
Dave
Dave
