My personal experience over the past 9 years has shown very similar results. When I started I used to always veg under 24/0 for a couple weeks, then switch directly to 12/12. I was convinced by all the people at the local hydro store to switch over to 18/6 for veg and see the results. Well I did just that and got about 1 lb. less than I was used to for the size crop I had. I tried again under 24/0 for only 1 week, then 18/6 for a week, then 12/12 for a week. This actually added about 7-10 days to my flower cycle and again, I came up shy of the norm, only about 3/4 lb. this time, but it took 10 days longer! After seeing these results I did a control group of veg for 2 weeks in 24/0 and two test groups. One group started veg for 24 hours for a week, then 18/6 for a week. The other was under 18/6 the full two weeks. All plants were put into the flowering chamber together and mixed together so light distribution was fair. I kept very detailed notes of this process. Here are my results: Plants vegged for 24/0 for two weeks- avg 1.886 oz per plant (65 days to harvest) Plants vegged for 24/0 for 1 week, then 18/6 for 1 week- avg 1.512 oz per plant (72 days to harvest) Plants vegged for 18/6 for two weeks- avg 1.559 oz per plant (69 days to harvest) The strain is White Rhino and plants are vegged under a 4' x 8 bulb HO T5 for the first week. Then vegged under a 1000 MH (conversion bulb for HPS ballast) for a week. Then all plants are placed onto a 4' x 8' table with a 1000W MH in the center and a 600W HPS on each side. After two weeks in 12/12 the MH is replaced with a 1000W HPS for the remainder of flowering. I have other friends that grow that swear by 18/6, saying they get better results with some down time for the plants to recover from the intense light all day. Personally, I repeated this same experiment 3 times before finally deciding to go back to the 24 hour veg for two weeks strait. It seems that the transition into flowering is faster when going from 24/0 to 12/12 than 18/6 to 12/12. This is just my personal experience so please don't castrate me for my posting. Just sharing what I have personally experienced, logged, tracked, and decided on. Each strain will react differently, and what works for me may not work for you.
Nope. It was this article that convinced me to try the 18/6. All the people I deal with at my local hydro store said I had to read the article and do things that way because it was "better." I call BULLSHIT! I tried, I tested, I recorded my results, and I veg in 24/0.