soooo....hi applesauce, ya saying replacing cfl with screw-in leds from the store? .....are they even in the same output ballpark as a 2700k 42w cfl? i dunno, i havent done the research and hoping you have as its time for me to build and i was going to go with 4-500w of cfl in a grow tent... i can get 9w and 11w led screw-ins pretty cheap.....1-2 bucks a pop....i ran a 600w cabinet ala Dr.bud style and it worked well but want to keep electricity usage down