Ask Ed Marijuana Grow Tip #29: 12-1 Light Cycle Theory

A theory is circulating Facebook about the 12-1 light cycle as an energy-saving technique that facilitates excelerated growth during the vegetative stage of growth. Personal attacks are irrelevant, here is the scoop behind 12-1:

Plant growth is based on photosynthesis, which produces sugar.

When sugar is combined with Phosphorus (P) and Potassium (K) it forms amino acids, which are the building blocks of tissue and plant growth.

The more light plant’s receive the more building block amino acids they produce, aka growth.

They certainly grow well under the 12-1 light cycle as being advertised, but only simply because they are getting more light. Although it saves energy, energy equals growth.

***Editors Note: Because marijuana is a short-day annual, it measures the length of the dark period to determine when to flower (ie: after summer solstice the dark periods get longer and longer outdoors. You can prevent flowering indoors simpy by interrupting the dark period. A flash of light, rather than a full hour is all that is necessary to interrupt the dark period, so more energy would be saved by simply shutting off the lights for a minute.

 

Comments
9 Responses to “Ask Ed Marijuana Grow Tip #29: 12-1 Light Cycle Theory”
  1. Dr. Courter says:

    Hey Ed, it’s been a while. I go way back with many Humboldt grower. A friend of mine grew in Salmon Creek starting in the early 60. In fact he was really the first to introduce Chitral to the region. He and I took a trip to Paki country to pick up seeds. I remember the days when Subcool was a trimmer in the field. Now he is considered a breeder?!?! What joke! He should of stuck with HVAC installation. This clown was stealing seeds and buds from us that’s about it SUBZERO is a pollen chucker at best. Anyway it’s sad to see this! Ed I still much respect for you, you my friend have street cred with me!

    • Battman says:

      Very interesting to myself. I believed he was from south Fla. with them tatts covering his arms. Some associate Subzero from somewhere down there.
      Been at this “shovel riding ” since 72 myself, first smoked in Barcelona, Spain in 65.
      “Q-Tip dabbers” aren’t breeders, nor the “paint brush” crowd , , , ,
      We free range cowboyz , , ,

      be well

      • Scott says:

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  2. Johnson says:

    According to studies, not all wavelengths of light can support photosynthesis. So those non-absorbed part of the light spectrum is what gives photosynthetic organisms their color (e.g., green plants, red algae, purple bacteria) and is the least effective for photosynthesis in the respective organisms.

  3. Dennis Ford says:

    12/1 is a fantastic method that works great. Growth is optimum because the plant needs rest as well as energy to grow properly. 12/1 is also only for Veg, therefore flower growth is moot. I use 12/1, and I am a champion for the method. It works great, and increased my plant growth by up to 20-25% as well as created closer nodes. Energy is important, but so is rest, ask anyone thats been up on energy drinks for 72 hours!

  4. jake white says:

    subzero pollen chucker, i wann hear more! explain man!
    -jake

  5. BigB says:

    Ed! This answer does not make sense?

    “They certainly grow well under the 12-1 light cycle as being advertised, but only simply because they are getting more light” – under 12-1, the plants are getting ONLY 13hrs light per 24hrs, which is LESS light than the usual 18/6-24/0 periods used!

    12-1 = 12hrs on – 5.5hrs off – 1hr on – 5.5hrs off.

    While the following is true, I think you meant “…simply turning the lights ON for a minute” ?!
    “You can prevent flowering indoors simpy by interrupting the dark period. A flash of light, rather than a full hour is all that is necessary to interrupt the dark period, so more energy would be saved by simply shutting off the lights for a minute. “

    • MendoCo says:

      I was also confused by Ed’s statement.
      I’m on my 3rd grow with this light cycle, in addition, the light cycle for my flowering has changed from 12/12 to 11 on/13off with an additional 15min off every week. While I can’t say as yet that my yields are consistently better, on the other hand they haven’t declined either!
      All in all my utility bills have been reduced by over 30%, it equals out to about 287kwh’s of saving per 1000 watts per month, I’m sold!

      • Rambo says:

        I am only guessing that the original though was that you could veg under 12 hours of light per day instead of 18 but still prevent flowering by giving the plants one hour or a flash of far red light to turn the PFR back into PR and thereby prevent the flowering response. This 12:1 VEGETATIVE cycle would reduce energy cost but slow growth rates. I think somehow this particular thought may have been clouded a bit by a thick haze of smoke.

        Maybe I’m wrong. I would love a better explanation if I am

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