the cost of createing the perfect enviroment in a grow room is costly,co2,dehumidifiers,box heaters,ac units,fresh lights,high end reflectors,timers to regulate the on off of air extraction and co2 replacement,great genetics,and the electricity to run all these,is beyond most peoples reach,i find the cost of electricity to create the perfect enviroment is very expensive,in BC X worked for Y and Y had tractor trailers set up around the province,some under ground some above ground in the end he settled for a pound and 1/2 per light after that it got expensive and time consumeing,i just find that most of the talk about 2 plus pounds per light is geared towards us spending money on all types of products to reach the holy grail,its like doing crack and chaseing the dragon.In every rosenthal,jorge,high times,cannabis culture,they all talk of a gram per watt for every 60 days of flowering,and they talk as it is the norm,but it is not the norm,but with out the great genetics nothing can happen,we all cant be arnold swarzenegger even with the same workout and diet.so is 21/2 pounds achievable,probably with a great strain and the perfect indoor enviroment,heck in canada its expensive just to keep us comfortable in our harsh climate never mind a grow room.