16 oz in a pound which people are pulling off of 600W's, but it does take time and skill. I read a grow yesterday where a guy pulled 9 pounds off of 6 600w's, so what is that, that is about 20OZ's off of each 600w, and 20 OZ's is 560 grams per light, almost the Gram Per Watt/GPW, as a matter of fact he pulled over 9 pounds and said that he usually pulls 10LB. Over on IC Mag, Mr Wags pulld about 14 OZ's off of a 400W in an ebb and flow with CO2 in one of those Canadien grow boxes.
Well, anything is possible.
Adieu