Quote Originally Posted by Anathema2121
Yeah, some plants absorb co2 they use during their dark cycle, but marijuana is not one of them. It is classified as a c3 plant meaning it uses the co2 it gathers during the light cycle and does not need a rest (dark) period. So sayeth Ed Rosenthal

http://cannabisculture.com/articles/3127.html
That's very interesting. I thought the separate cycles were essential to all higher plants. But it makes sense; if you can veg 24 hours...
Thanks!