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24 Hours of Light

Discussion in 'Newbie Central' started by 420Farmer, Sep 17, 2006.


    420Farmer Active Member

    Is it possible to keep a vegging crop (2 weeks old max) under a continuous 24/7 Light Schedule without damaging them?

    skunkushybrid New Member

    Yes. I've heard that this is true. We kept ours under continuous light for their 2nd week of veg' then switched to 18/6. Not sure about doing it all the way through. People will probably tell you different but I wouldn't do it. I know what I'M like when I've had no sleep.
    Widow Maker

    Widow Maker Well-Known Member

    You can leave them on 24/7 untill you decide to bud them.

    jacgrass420 Well-Known Member

    which is the best for the plant tho. cuz iv had mine on 24-7 for about a week and they look ok but then again would they grow faster or maybe more potent if i let them have darkness? just want the best for the babies...you know

    skunkushybrid New Member

    That's how I thought of it too. I don't know whether I'm lying to myself but I'd swear mine grew more throughout the night. Maybe it was the time scale but as soon as we gave them 6 hours kip they just seemed to shoot up.

    SWMElite Member

    Marijuana store up their light as energy during the day, and during the dark hours the plants stretch and grow, releasing the energy they have stored. Using a 24/7 light cycle allows you to slow the growth of the plant.

    You add darkness to promote vegetative growth, and a 12/12 to induce the flowering cycle.
    cheesefish likes this.

    YEAHRIGHT Member

    im doing it right now, friday will be day 16 under 24hour light then im flowering

    PhishPhan13 Member

    what about 36/12 for veg? then they get a lot of light AND a lot of sleep.. they are called SUPER DAYS.

    Viagro Well-Known Member

    Marijuana belongs to the type of plant that doesn't necessarily need darkness. This plant does not sleep (see Ed Rosenthal). I grew some dank Fast Bud 24/7, and with only one Kessil led light. That's a mere 30w of light (remaining 6w is the fan). I did it to prove something, but the the point is that many stable autos can handle 24/7. What I did was have the timer set at 1hr45min on then 15 min off, throughout. I had a small auxilliary bulb to keep things slightly lit, which gave the light gathering cells a break, and allowed them to transfer the energy they have been manufacturing throughout the plant. This does the same service as a lightmover, and it will make for a much happier and healthier plant. Plus the cool down extends the life of my Kessil coniderably. I like this method for autos. Good luck.

    Viagro Well-Known Member

    This is a direct quote from Ed Rosenthal whom most of you know is a marijuana growing guru:

    ...marijuana plants photosynthesize as long as they receive light as well as water, air, nutrients and suitable temperature. Photosynthesis is the process in which plants use the energy from light (primarily in the blue and red spectrum's) to combine carbon dioxide (CO2) from the air and water (H2O) to make sugar while releasing oxygen to the air.

    Plants use sugars continuously to fuel metabolic processes (living) as well as for tissue building. The plant combines nitrogen (N) with the sugar to make amino acids, the building blocks of proteins. They are the substance of plant tissue. When the light is off, the plant's metabolic processes, respiration and growth, continue.

    The plant can photosynthesize continuously so it produces the most energy and growth when the light is on, continuously. Continuous light does not stress the plant, which reacts somewhat mechanistically to it.

    Plants under an 18-6 light-dark regimen are producing sugar only three quarters of the time. They are thus growing at only 75% of their potential. Leaving the light on continuously will result in bigger plants, faster, which leads to higher yields."

    "The following information is straight from Greg Green's "The Cannabis Grow Bible"

    Cannabis is a light demanding plant. Professional growers keep the light on their plants using the 24/0 photoperiod for this reason. Plants that grow under 24/0 flourish and do not need a quantity of darkness in order to rest and perform photosynthesis properly. Plants that are grown in optimal conditions under 24/0 light regime grow vigorusly and the benefits of a 24/0 photoperiod can be seen actively in the results. More nodes are formed, more branches are created, leaf numbers increase, the plant is growing at its finest.

    Some growers opt to use 18/6 as their photoperiod. This is 18 hours of light, six hours of darkness light regime. Under these conditions the plant will grow quite naturally but not as vigorously as the 24/0 photoperiod.

    The 18/6 photoperiod expels 3/4 the amount of light that a 24/0 photoperiod does. Although this does not mean that a plant produces 1/4 less leaves,branches and nodes under the 18/6 photoperiod, it certainly does show the correlation between light and cannabis growth. As we have said already, cannabis is a light demanding plant. There are no problems associated with 24/0 and although some have attributed cannabis sexual dysfunction (the hermaphrodite conditon) to 18/6 photoperiod these problems are actually the result of heat stress.
    A 24/0 photoperiod requires that your grow room temperature be kept well monitored. The 18/6 option is cheaper to run. You use a quarter less electricity and this will have an impact on your electricity bill. Also the 18/6 photoperiod will generally extend the bulb's lifespan. During the 6 hours of darkness the grow room is allowed to cool down for this period but a well maintained good grow room setup should not require a cooling down period.

    24/0 and 18/6 both share the same problem though. Once you start the photoperiod you should keep that way especially when the plants near maturity (the preflowering stage). An irregular photoperiod can cause more males than females to develop. It can also cause sexual dysfunction to appear. Whether you choose 24/0 or 18/6 as your vegetative photoperiod try to keep that photoperiod unitl your plants are mature enough to express their sex."
    24/0 is superior insofar as plant growth

    smallclosetgrowr Well-Known Member

    i havnt botherd to read the whole thread but i can tell u that proven tests have been done and its only worth keeping them on 24/7 for the first 2 weeks....anymore then that and there growth rate isnt worth the amount of extra light $$$ your paying.and i wouldnt sugest 24/7 even if u can pay the lighting bill because plants need to respire aswell as transpire.Google respire.

    Viagro Well-Known Member

    Bogus. Read previous entry.

    CoffeeBreak Active Member

    i did 6 weeks
    plant was 4.5 feet at end

    lowrider2000 Well-Known Member

    its up to you, but it will not damage the plants ------i vegg for 1 month and put st8 to flower works just fine and i dont need an extra timer.......
    Father Earth

    Father Earth Active Member

    24/7 light cycle has its advantages and its disadvantges. It does boost growth, yet too much of it and 18/6 will become more benefitful. Its also less stress on the pockets.

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