Hi tyler_medeiros, Typically they say 20 gallons per Angelfish. I've always felt like that was a little overkill. Angelfish aren't a large bodied fish, but I would still only go with about 4 in the 90 gallon with 5 Dwarf Neon Rainbows. You want about 5 for them to shoal and they only get about 2 1/2 inches long. With 4 Angelfish, 5 Dwarf Neon Rainbows and 2 Cories you'll be pushing the bacterial filter a little, but really shouldn't be to difficult to manage. With a lot of greenery (suggest artificial) it will make a gorgeous tank.