i run 18/6 personally.

i think its just a matter of preference, 24 hrs will probably ( ive never tried it )
give slightly faster veging at the trade off for more power, but then if your vegging longer with 18/6 your going to use more power anyway.

i go with point 3, its more natural for the plant.
babystarbud Reviewed by babystarbud on . Why 18 hours works for me O.K here are a few reasons to run your veg 18 hours instead of 24. 1. You can run 25% more wattage for the same money. (so a 250w on 24 will cost close to a 400 on 18). 2. In a sog or perp harvest where your veg is running constantly 24 or 18 will have no effect on yield though it will have a large impact on electricity consumption. 3. It is simply more natural for the plant. To be fair I will say that if you have to run the same light for veg and flower 24 may speed Rating: 5