Quote Originally Posted by JohnnyPotGrower
no i dont think it directly effects output. but the shape of the light will effect how much of those lumens reach the plant. if i am correct, the elongated CFLs are the best, especially if you are able to hang it horizontally above the plant. Reflectors would also obviously increase the efficiency. So althought the shape/length doesnt determine lumen output, it would be wise to find the most effective way of getting the most light possible going towards the plant.

JPG
Dude I vegged for several grows using just the 4ft(48) inch shop lights with the flourencent tubes.........each tube throws off about 2000 lumens but gets weaker as you get closer to the ends of the tube......I found my plants that were in the middle of the tube always did better then the ones closer to the end of the shop light,I heard the cfl can do alot better but from my own exsperience I did pretty good by them.....if you have enough of them you can get alot of lumens happening and they are cheap ass! to run, won't even notice it on the power bill! but as far as deep penatration of light into the leaf canopy it won't happen with flourecent tubes,thats why when I grew with flourecents I always went SOG...