I couldn't find any difference except for the penetration issue ....I have 3 42w(150w equiv each) with 2750 lumens each and a temp of 2700kelvin..I'll be using these to light 1 square foot~(flowering) so I have 126W(450w equiv)with a total of 8250lumens....I'm well over the 50w/sf min and closer to the 10000lumens than the 5000lumens min needed...I have 4 strains started...NorthernLights #5,Skunk#1,BigBud and WhiteWidow...I also have 3 unknowns and 5 "MysteryMix".....I know the 3 unknowns are a southernQuebec indoor/outdoor strain but as of yet,unidentified...

I havent decided which strain will "volenteer" for the experiment but I'm sure one of the girls will be more than willing...the rest will be under my faithful 400's...
THE MEDIC Reviewed by THE MEDIC on . Lumens CFL/HPS I've always used single or multiples of 400watt HPS lights for a 3'X3' canopy,this gives me around 5555 lumens sf... my question is whats the differents between the 400W giving 5555 and say a 85W CFL giving 5500 over the same sf? besides needing 9CFL's to cover the same area.. Rating: 5