it's in the february 2007 issue. it says 8th hydro report on the cover. in the groworld section it has an article called "the pot whisperer!" by The Medicine Man and Sister Sativa. It says:

"During the vegatative stage, the lights should be on for at least 18 hours per day. At about two to three weeks, turn off the lights for 12 hours two days in a row. This will cause the foliage to thicken."

Now i sort want to believe this because who ever wrote it must know what they are talking about...it's high times!