Trying to put together a tank via the "cookie cutter method" is not such a good idea... Everyone's tank is slightly different, and there are several different factors, such as filtration, individual fish size/weight/temperament, and even light, that go into determining how many fish can go into "x" amount of space. It's more of a trial and error thing than something you can take directly from a book (and I know it isn't much help to say that...). As a rule, lighter stocking is always better. Err on the side of safety.... Put one fewer fish in there than you think you should, that sort of thing...