A locked door will ALWAYS work better than a keep out sign. You only have to have the room locked -no sign required by law. I wouldnt recommend advertising your grow with one either. As for the whole 12 plant question, it is in regards to propagation, not weight. If you can't get 2.5 oz with 12 plants I agree that you are doing something (or as lot of things) incorrect, but the 12 plants is so you can have continuous medicine in the sense of a purpetual. If you are making sure to stay in the confines of the law, you probably wouldnt run all 12 in flower at once. You will have a few seeds popping/clones rooting, then a few vegging, then a few flowering. This way you never have a down time you are without medicine. If you run all 12 at once in flower, you will surely exceed your 2.5 oz max dry weight plus you cant have anything else like clones/seeds or vegging plants going in the meantime.
