24/0 vs 18/6 in the vegetative cycle

Discussion in 'Growing Marijuana Indoors' started by Delta223, Jan 31, 2010.

  1. Does a 24/0 cycle really produce larger plants in less time, or is it overkill? What do you guys prefer?
     
  2. I have done both and keep mine on 18/6...didnt notice a big dif. with 24/0 except my elec. bill was bigger.

    Numb
     
  3. Plants will only utilize only 18hrs of light

    ...I firmly believe that 24/0 will actually stress a plant.

    All living things need rest..you wouldnt stay up 24/7 would you?

    same thing applies to your plant..


    18/6 is the way to go, unless you want to spend more your electric bill
    which is totally useless
     
  4. I don't agree at all. Not a single word.
     
    • Agree Agree x 1
  5. i never said you had to agree..

    i'm giving him my personal opinion

    if you want to spend another bill for electricity, then thats your business
     
  6. I used both in my grows.
    My first 24/7 had trouble flowering because I didnt have it on a proper schedule,
    I ended up witha 6 foot female, that wouldn't flower.

    My second time around 24/7, I noticed the same height and growth, and I had it on a proper timer, and schedule. Huge maple leaf sized fan leaves.

    Third time around, I've done 18/6, same strain, same nute sched, and I didn't notice a difference other then the leaves were more less full looking and smaller, like maple leaf sized.
    Overall, I wouldn't say theres too much of a difference,

    I know clones should be on 24/7 , go give them the most chance of living.
    And Veg is 18/6, 24/7, its personal really.
    No light is too much light for a plant, unless it's trying to flower :p

    Quote + Correct me if I'm wrong anywhere gentleman. :)
     
  7. Personally, I go 24/0 for 3 weeks then 20/4 for 10 to 12 more weeks (depending on how close to maxing out the available space the plants get), then 12/12 for the flower until done. But, I have no scientific reasons for doing so. Usually runs me $30 a month at the beginning for my 400W MH/HPS
     
  8. The above statement is clearly from someone who does not know what he is talking about. Read below from someone who does.

    Need the dark


    By Ed Rosenthal -
    Do plants need a dark period during the vegetative cycle?
    [​IMG]Does marijuana require a dark period during the vegetative growth stage? I recently read a grow book that advocated an 18-6 light cycle during the early growth stages.


    One way in which plants are categorized is by the way they gather and handle carbon dioxide. Cannabis is a C3 plant. It uses the CO2 it gathers during the light period, when it is photosynthesizing. Plants designated C4 also gather CO2 during the dark period for use during the light period. Many C3 plants, including cannabis, do not need a rest period. They continue to photosynthesize as long as they are receiving light.
    The plant's photosynthetic rate determines its growth rate because the sugars are used by the plant to build tissue and for energy. Cannabis under continuous light will grow 33% faster than the same plants on an 18-6 light regime.
     
  9. Thanks very much Rumple, that's good info to have =)
     

  10. how is this possible, how can it grow 1/3 faster with only 1/4 more the light, how do they come up with the numbers? im not dissagreeing, i personnaly keep my lights on for 18/6 because i have personally noticed with 24/0 theres more stretch on my plants than with 18/6
     


  11. I wasnt saying i knew everything, I was simply dropping in my 2cents for what has worked for me..not everyone has the luxury to leave on an HID lamp 24/7.

    You can gather all the Class-a information you want...personal experience is better than
    anything you can read from a book. so basically you're saying expirementing is wrong.

    Instead of correcting me in a civil matter, you tend to be a fukin dick about it..

    go ahead and tell me how im wrong.
     
  12. All C3 Metabolism Plants go through a nocturnal process called 'Dark Respiration'. 'Dark Respiration' is basically a multi-part process of creating energy by oxidizing sugars. This energy is required for biosynthesis and several important metabolism functions. It is critical to the overall plant growth rate.

    Night-time CO2 levels in excess of 900 PPM cause the stomata of C3 plants to close thus inhibiting 'dark respiration' which consequently deprives the plant of the energy required to achieve maximum potential. It is very common to find excessively high night-time CO2 concentrations in sealed grow rooms and where pilot burners are used.

    It is possible to control the plants 'dark respiration' rate by altering the CO2 concentration.

    At night C3 plants release CO2 which should be evacuated whenever the level exceeds 600 PPM. This will provide an ideal respiration rate.
     
  13. Same here. 18/6 always look fuller even though smaller foliage and shorter. Maybe the 1/3 growth mentioned was height?
     

  14. Owned?..what are you 15?

    i was clearly stating that not EVERYONE has the liberty to run their lamps on 24/7..
     
  15. Very good point. It looks like Ed's maths is a bit off. Smoking weed and math don't mix it seems.
     
  16. lol :)

    HIS math was correct.

    24/18 = 1.33 = 33% increase

    Your mistake is in thinking that the ratio of light lost when using 18 hours instead of 24 must be the same

    18/24 = 25% decrease.


    Think about it guys... 6 extra hours on top of 18 hours IS 33% more
     
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  17. Jspec2ner, I don't think a dark cycle during veg is bad for your plants at all. I did not agree with your statement that they needed one.

    I have friends who turn off during the peak heat of the day and some who need to quiet the ventilation during high traffic near their grow room.

    To say it's better, will depend on your needs and circumstance.

    I have been growing the same strain for well over four years in controlled environment. We have been testing and debunking lots of myths and wives tales about what works and what doesn't. I have been working real hard to get the total cycle time down, while maintaining quality and yield.

    The single most effective change I made to reduce cycle time was leaving the lights on during veg. I was a hard core 18/6 believer. It took three complete cycles to turn me off of 18/6, because I did not want to believe in something that seemed so wrong against nature.

    Most people see positive change every time they open the door to the grow room. Every grow looks better then the last. This is the main reason folks still use 18/6 light cycles, mist with carbonated water, and cut the tops and sun leafs off their plants.

    Don't get caught it in the flame war, even when you are not the one to start it.
    Peace, R.
     
  18. Damn, I stand corrected again! The only math that is screwed up is mine.
     
  19. ^This.

    It is equally true that reducing 24 hours of light by 6 hours is a 25% reduction. The same equation run two different directions yield different percentage results because the base (denominator) is different: 6 compared to 18 vs. 6 compared to 24.

    Just like when the stock market drops 50% it then has to double (100% gain) from that point to get back where it started...
     
  20. The 24/0 vs. 18/6 debate has raged on for quite some time, and I have no expectation that it will be resoved with this thread. Suffice it to say that both work, the debate is not if one works and one doesn't, only if one is better than the other. There are experiences and evidence to support both sides. Ultimately choose one you are comfortable, experiment if you will, and either way is a path to good results.
     

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