Ya that is probably true, but to be honest I have tried to get the information out of this guy on his getting 4 pounds out of his set up and he will not respond. I am very skeptical that someone is getting 4 pounds out of that setup because well like growsince79 mentioned it would be a record. Usually every so often someone comes on this site with claims that are not really achievable and we need up hearing things like well I hand my plants for 3 days and them weigh it
or I trim and weight everything
or as listed above I weight the whole plant after I cut it down.
To be honest anything over about 2 1/2 pounds per light is pretty darn good and not many can get those numbers. So when someone comes on hear with claims of getting 4 pounds a light people are skeptical because as stated is would be a record.