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Veg Light Time

Discussion in 'General Marijuana Growing' started by batbud, Dec 31, 2009.


    batbud Member

    I'm just getting started with a closet grow room with a 400W ballast set up.

    I've got five clones going in soil and they're looking healthy.

    How long can I leave the MH light on for? I've been doing it basically whenever I'm up, so about 8AM to 11 PM. Is that right? What is the optimal amount of time for VEG GROWTH? Would it hurt the plants if I left it on all day and all night for a couple of weeks?



    dutc2006 Well-Known Member

    Leave the lights on as long as you can. you are now on 15 hours light/7 dark. This is fine because the plant will continue vegetative growth as long as the days are longer than the nights, but the more light they have the more they can grow. Some plants require dark cycles, cannabis is not one of them.

    chronik4lyfe Well-Known Member

    yeah the more light the better in veg growth.. u might wanna invest in a timer having ur plants on a erratic light schedual can stress them quite a bit.. might even end up tricking em into flowering
  4. Opinions vary greatly on this topic. I personally like to let my babies get about 18 hours light and 6 completely dark. We are ultimately trying to mimic nature. It is understood that cannabis can grow with a 24 hour light period but I do not do this for a few reasons.
    1) When a plant is in it's dark period, it uses sugars built up throughout the day from photosynthesis to continue cell production. If you train your plant to never have to use these natural mechanisms within, come flowering...the plant has not needed to use this surplus, EVER, and therefore is not trained for dark cycle production. How good are you at something you've never had to do? (This is only my theory, never tested or proven.)
    2) Save money! With 6 hours dark, you are cutting 25% out of your running times. I like to give my equipment time off and allow for temps to drop and bring my rez temps down. But, as I said, it is merely an opinion and has worked for me in the past. Whatever suits your grow style, availability of resources, time frame (I need buds NOW!) and desired yield will all determine your grow plan.

    jawbrodt Well-Known Member

    Yeah, you should keep them on at least hours longer. 9 hours of darkness is a little too much, and will slow down your vegging. Try 18/6, as the above member suggested, you be set up perfectly. Some people use more light hours than 18, but it's not really necessary. That's your own decision, but i think it just uses more electric, and believe that plants need that darkness to rest.

    batbud Member

    Thanks for your reply!

    I agree with your recommendation. Naturally plants get darkness and it makes sense there might be some adverse effects of giving them 24 hour light. It just doesn't seem right to give them 24 hour light. I'm going to try the 18/6 hour cycle

    Do you have any recommendations for timers. I want to incorporate an air filtration system with my timer as well. I'm thinking the air could kick on ever 30 to 45 minutes for 10 to 15 mins to clear out the produced O2 from the plants. (I'm going to be working in a small, 6'x3.5'x5' sealed grow box) I'm also thinking about having a CO2 container on a valve setup that would kick on for a short period of time after the air exchange to resupply the plants with CO2.

    Specifically I'm looking for a control unit that can turn off/on multiple power sources (three so far) on a programmed schedule.

    I know this is pretty specific but I would like to work on getting a good, cost effective grow-room available for patients to grow their own quality medicine at their own discretion.



    thebeadog Member

    this is my first post, but i have done 3 runs (not counting current sour diesels on day 8 of flowering). i have always run at 24/7 during veg and have always had amazing results! as long as your temps are not extremely affected, and you can afford the electricity, it works wonders. and im no botanist, but im quite sure you dont have to TRAIN your plant to flower. do you have to train yourself to sleep? or to use up energy in your body? dont think so. mother nature is a wonderful thing (mostly). but im not saying anyone is wrong. 18/6 may slow down your veg, but you wont even notice unless you run one under 24 and one under 18 at the same time. not to mention saving a hell of alot of money over time. whatever works man. and since this post is like 5 months old, i guess your already done so good luck on the next grow

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