When to switch to 12/12

Discussion in 'General Marijuana Growing' started by dertyoldman, Dec 19, 2009.

  1.  
    dertyoldman

    dertyoldman Member

    New to this an all. Had a quick question. I have 2 plants going right now. They are about a foot tall. My question was when should i switch to 12/12 to see if any are female? Should i still veg them for a while even though i dont know if they are fem?
  2.  
    boggermania

    boggermania Active Member

    if it was me i would flower now a foot tall is plenty and you want to figure out male or female and get the males away from the ladies if your gonna clone then you might want to think about getting a nice female out and put it on a veg light schedule
  3.  
    dertyoldman

    dertyoldman Member

    yeah thats what i was thinking cause i dont wanna really waste anymore time on them if they aint fem. Thanks for the quick reply
  4.  
    SparkUm

    SparkUm Member

    I'd definetly flip them at 1 foot due to the space I personally have, what strain are you running?
  5.  
    Silky Shagsalot

    Silky Shagsalot Well-Known Member

    i switch to flower at 12". but that's with a 1000 watt light. if i had a smaller light, i'd flip them sooner.
  6.  
    Illegal Smile

    Illegal Smile Guest

    The decision should be based on target final height. If you have the space bigger plants mean bigger yields.
  7.  
    Silky Shagsalot

    Silky Shagsalot Well-Known Member

    not necessarily true. what good is a 4 foot plant with a 400 watt light? the light will only penetrate so far into the canopy. then you've a whole lot of plant, stretching to get a little bit of light... also base your flip on vertical space available.
  8.  
    dertyoldman

    dertyoldman Member

    Strain - Honestly not sure. My buddy grows and had some seeds laying around so he just gave em to me.

    Space - I have at least 8' vertical space.

    Im using a 400 watt MH right now and i have a 400watt HPS i was gonna use to flower.

    Im just worried about wasting anymore time in veg. Would suck for them to be males.

    So from what im gathering from you guys at about a foot high i could/should switch to flower to see if i have any fems then start clones from that correct?
  9.  
    dertyoldman

    dertyoldman Member


    So with a 400 watt MH you would switch them over shorter than a foot?
  10.  
    abe23

    abe23 Active Member

    Yea, you can switch now but it might pay off to wait until they grow another 6 inches or so if you have the space and the patience. Your plant could mostly indica (a lot of indoor seeds are) in which case it will grow to maybe two feet once it starts to flower. You might also have a crazy sativa, in which case you'll end up with a 6 foot tree if you flower now.

    Ideally, you don't want them to grow over 3 feet with a 400w because the bottom branches won't get any light if they're any taller. Then again, if you have the headspace and trim off the crap at the bottom, it doesn't really matter. And if you only have two plants under that one lamp, you'll want to give em some good veg time if you want to pull a nice harvest.

    If I were you, I would give it another week or two, take 6 clones from each plant and then switch to 12/12. If they end up being females it will be worth the wait and if they're males, you'll at least have learned something....
    dertyoldman likes this.
  11.  
    dertyoldman

    dertyoldman Member

    thanks for the insight
  12.  
    diSplACed

    diSplACed Member

    In the last 10 months I have been studying as much as I can about growing marijuana. Almost all the grow web sites I have looked at suggest you switch to 12/12 at 12"-18". It is my understanding that Cannabis plants (indica/sativa) usually double in height during flowering stage. Indica plants are usually small in nature. I have a GDP thats only 18.5" vegged for 7 weeks, flowering for 4 weeks.

    I too am running my grow with a 400 hps. I didn't have the money for a grow light and wasn't to sure about cfls
    so I vegged for 7 weeks in a 2x2.5 by 9' closet. I only have three plants. I am currently in my 4th week and I am seeing nice bud formation.

    ABE said it best. Good :joint:
  13.  
    Silky Shagsalot

    Silky Shagsalot Well-Known Member

    it just doesn't make sense to have more plant than your light/environment can handle. with small wattage lights (like 400) i suggest doing a scrog. a thousand watts will penetrate roughly 12" into the canopy. after that, the lumens doing much of anything falls off dramatically.
  14.  
    dertyoldman

    dertyoldman Member

    ok and rather than start another thread. In regards to vegging i have done some looking around and some people veg 24/0 some 18/6 some 14/10. What if any effect have some of you had with these different time schedules?

    Im doing 18/6 because thats what i see the majority of people running. Just wondering for future grows.
  15.  
    sweetsmoker

    sweetsmoker Well-Known Member

    the higher the light period the shorter the nodes will grow and so the plant will stay shorter.. plants stretch during the dark period, thats why 18/6 is generally bettre for gd spacing of nodes and time to height ratio :)
  16.  
    dertyoldman

    dertyoldman Member

    Last question


    Any advantage to running 24/0 for a few days throughout veg? a friend of mine has said he does that a few times during veg
  17.  
    sweetsmoker

    sweetsmoker Well-Known Member

    at seedling stage i will run em 24 for a week then switch after that mainly for electric purposes:) and ask as many qs as u need 2 m8 i sure do its wat the site is 4
  18.  
    Illegal Smile

    Illegal Smile Guest

    I always veg 24/7 and see no reason to deny them light/energy for 6 hrs a day.
  19.  
    sweetsmoker

    sweetsmoker Well-Known Member

    how long do u veg at 24 for illegal man and what heights do u acheive in that time im always keen to see how others do their thing
  20.  
    businessmen

    businessmen Active Member

    I like 18. Info I can find claims 24 only gets 5-10% more growth then 18. And your using 1/4 more power. Im just a nature lover like that, 24 seems too unnatural....

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