If you go from clone which you really need to in order to take advantage of a SOG, you can put 4 plants per square FT meaning about 24, but 2 per square FT will still be considered a SOG as well. I think that with 2 plant PS FT you can get about 10 to 14 G per plant depending on the strain. with 4 plants PS ft about 10 g IMO.
Adieu