No one wants to argue with you about your 31 plant set up that we have never seen, nor do we want to repute what "your Friend" did whom we've never met. all we can do is tell you from expierence that math while your looking at plants is not science, are you an expierenced grower than estimate and see what you harvest, then do the math and see where you come in at. OR just continue the tradition of every Newbie that signs up here and Play the GUESS MY YEILD game, and start shit with people giving you thier honest expierence answers...your call rookie....PEACE