I couldn't give you an exact, accurate number, but I know for a fact many professional growers like Ed Rosenthal and Greg Green recommend at least least 20 watts per square feet.
Sensi Super Skunk Reviewed by Sensi Super Skunk on . Day 15 since germination inca spirit hey everyone my buddy and i will be posting pics threw out our whole hydro grow and were starting here day 15 since germination any comments are appreciated sorry picture is a lil blurry will be doing daily pics this is Inca spirit f1 hybrid Rating: 5