Light Cycles

how long should the light cycle be they have been growing in a window for about 3 weeks (SLOW) and i just got the lights today. ive seen 24/0 and 18/6 for veg. I have 2 40w 12T fluoros and 2 26/100w cfls...Which is best any help would be great

go with 18/6. When you're growing indoors, you're basically looking to mimic nature as closely as possible. 24/0 is too far off the mark and considering that plants outside deal with not only nite time, but dusk and dawn too, even 18/6 is plenty of light.

happy growing!