I don't see any place that says how to grow 2 pounds. But depending on your light and if it is a wet or dry weight, 2 pounds seems realistic in my opinion.
Yea thats why i feel it's so ambiguous. He says it when the webpage loads but he never actually goes into detail and just talks about making the perfect room... I thought 2 lbs of dry but if its wet then that would make more sense.