You're going to hear a lot of different theories on this one so it'll probably chalk up to you making your own decision.

Some people will say the darker cycles promote more root growth. I had a friend that took a horticulture/botany class. They taught him that the "more root growth during the dark cycle"opinion, was just a myth that floats around.

He also told me that plants will grow faster with 24/0 because photosynthesis never stops. There may not be much of a difference, but I agree with him.
The Grim Reefer Reviewed by The Grim Reefer on . 18/6 vs 24/0 and growth speed? Right now I'm vegging a plant under about 300 watts of CFLs on 24/0. I'd like to switch to 18/6 to let things cool off and save a little electricity. On the other hand I'm really desperate for weed so I want this plant to grow as fast as possible. Is there much of a difference in how fast the plant will grow between 18/6 and 24/0? Rating: 5