It depends on the strain some don't grow well under 12/12 and yield very poorly..
Growing 12/12 the plants tend to be short an mainly grow one big cola the good thing about this method is harvesting in 2 months (3 for sativas) from seed because you skip the vegitation cycle.
[Quoted for fart]"This thread is devoted to an excellent method of growing our favorite plant. 12/12 From Seed is a proven way to grow pot, and produces yields up to 1 gram of dried bud per 1 watt of electricity consumed (eg: a 400 watt HPS light is able to produce a harvest of 400 grams). It is a very good choice for growers who have a limited amount of space to set up their gardens. The cannabis grown this way is potent, sticky, and yes
stinky. Most pot plants suffer no ill effects from being grown under this light regimen.
Typically, in traditional method, the cannabis cultivator will start their plants with a lighting regimen that provides anywhere from 18 to 24 hours of light a day, called the vegetation phase, to make the plant grow as large as possible, increasing the amount of budding sites on the plant. Once the plant has grown large, it is forced into flowering by switching the lighting regimen to 12 hours on/12 hours off. This results in plants that produce copious yields, but take up considerable space.
12/12 From Seed eliminates the vegetation phase. As soon as the seed sprouts through the surface it is given a light regimen of 12 hours on/12 hours off. Plants grown this way do not grow as tall as they would if given a vegetation phase. The shape of the plants is also different, losing much of their natural bush quality. Our plants tend to be shaped like a pole, with the main bud formation happening along the main stem of the plant. This allows the grower to fit more plants per square foot/meter. It also makes possible gardens in spaces that growing larger, bush-like plants would be impossible. The shorter height of these plants also works in concert with the limited penetration distance that exists with any/all forms of indoor lighting.
Other than the difference in the lighting regimen, growing cannabis using this method is the same as the more traditional way. You still need to learn about the other important factors in growing a healthy garden, such as; proper nutrient levels; maintaining the correct PH level; controlling temperature, humidity, and odor; and providing ventilation. Because we are starting from seed, most of us use soil as our medium, although other mediums may be used. Other than that, all other personal choices to control the environment is the same as growing any other way.
This method does have its critics. Most of these critics have never tried to grow this way, they are just passing along commonly held mis-information without having actual experience. The main criticism is that the yields gotten from this method are miniscule and not worth the time involved. We challenge that, with the experience of a grower called Atmosphere who gets 1 gram of dried bud for each watt of electricity used (that would be a harvest of 8 ounces from a 250 watt HPS light!). Atmosphere had a thread back on Overgrow, which is where many of us first encountered this method, and he is held in high regard among folks who grow this way. He visits this thread and provides solid information based on years of experience.
Some critics claim that the amount of the main cannabinoid, THC, produced by plants grown this way is less than plants that are allowed to mature with a vegetation phase. This opinion is based on a study done many years ago, well before modern gardening techniques took hold, and almost certainly did not test any plants that were grown using this lighting regimen. New tests must be done, thats all there is to it. More importantly, the empirical evidence from those who have grown this way, and the experience of their friends who have smoked these plants, is that this cannabis is just as potent as any they have ever smoked (strain variety taken into account, of course). If there is any difference in THC percentages, it is minute, and not noticeable to the cannabis consumer."[/Butt clap}
