Will a black light work

Discussion in 'Grow Room Design/Setup' started by Grassmann1, Oct 8, 2003.

  1. weed no,how much fun i had in a hotel room yes
     
  2. Why is this a sticky. Makes no sense at all.
     

  3. HAHA totally agree. So many people ask this question over and over again though so eh saves me from answering questions...
     
  4. you shouldn't use black lights to grow with however if used properly you can use a black light to increase the amount of THC. or at least that is what i have been looking into. I haven't tried it yet by but during some periods of our growing if you were to put a black light on for maybe for 5 to ten mins a day the plant would produce more THC to protect itself from the uv light. When i try it am gonna start by turning the black light on a week into flowering for three or four min to see the results.

    so remember you cant grow with a black light but you can produce more THC.
     
  5. sorry if this has been stated, i read pages 1-3 and skimmed the rest....

    this link was posted earlier, should post it again: http://cannabase.com/cl/bcga/bcga/uv.htm
    this seems to say UV (b) is useful. i have not read the whole page yet, but is UV A/C useful in plants?

    If we are trying to mimic the sun, then these bulbs *are* useful.....but not needed to get good pot. but the sun does produce these wavelengths, as do black lights...this cannot be disputed.

    something i saw no mention of is the fact there are 2 main types of black lights.
    the 2 types are called

    BL (black light) has some visible spectrum as well (not filtered glass)
    and BLB (black light blue) these use a filtered glass to filter out the visible blue/violet.

    Black fluoros are 315-400 nm aka UVA
    UVA long wave 315-400 nm
    UVB medium wave 280-315 nm
    UVC short wave 100-280 nm (germicidal)


    i scanned some pages from my notes/books on this, should you be interested in reading :)
    [​IMG]
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    [​IMG]


    from my understanding growing weed (and most plants) is like this.

    they are green because they want to absorb the red and blue ends, green is somewhat unused by chlorophyl (which is green in colour) and the main photosynthesizing part. Caretenoids are reddish (yellow orange etc) and are therefor able to take in some more green light.

    so in order to grow they mainly need the red spectrum (650nm +/-) and the blue spectrum (450 nm +/-).

    this is all well understood by most, and can be found readily onmany websites and books.

    *IF* UVA helps THC production, then black would be good *supplemental* lighting, but because they (black lights) lack most/all of the visible wavelengths that plants like to photosynthesize (400-700nm) they cannot stand alone to grow a plant.

    to recap you must have the visible spectrum avaialble for plant growth because they only eat what we only see :)

    UVB is mentioned as being good for THC production (see link above). UVC i cant see being good as it is used to kill living organisms.....but i dont know for certain? eitehr way i dont weant to be in my grow area with a germicidal lamp looking down on me :(
     
  6. #86 bigjinc, Oct 23, 2008
    Last edited by a moderator: Oct 23, 2008
    UV light for plants helps form bigger bud. The facts are posted around the internet. It will not grow your plants but a low wattage UV light 5 hours a day during flowering will produce bigger and better buds. Note again this is supplement light to the light you are using. Give it a shot and post your results on a new thread:rolleyes: Make sure your light is UVB for the proper spectrum
     
  7. #87 Version 2, Nov 19, 2008
    Last edited by a moderator: Nov 19, 2008
    There is a MAJOR difference between a blacklight and a true UV emitting bulb. A blacklight makes shirts blue, a UV emitting bulb is what you would use to keep your pet lizard healthy. This a UVB bulb: Zoo Med Reptisun Compact Flourescent UVB Lamp

    I haven't used it personally but the grow journals I've seen that use UVB bulbs, they are used as a supplemental light, and their main effect is to get the plant to grow more trichs, not get fatter buds. Some one once explained to me that pot plants grow trichs partly to protect them from UV rays, I don't know how much truth is in that, but it makes sense.

    @subherbz: The way I see people use UVB bulbs is keeping them on whenever the other normal lights are on. I don't think 5-10 minutes a day will do anything to be honest. Just turn the UVB off entirely a day or two before harvest.
     
  8. all of you amatures busting on these newbies is extremely ineffcient. their just asking a little Q and A and you think your cool being smart ass's. got news for ya "douche bags"
     
    • Like Like x 1
  9. UvB light on this thread, beyond the requisite supraUv light already illuminating the subject re "black" lights, has obviously fostered increased trichomes here (us) thus making a stickier end product, No? :smoking:
     
  10. Thats some good feedback there douche.
    Way to contribute to the community.


    And no I don't think a black light will work.
     

  11. absolutely. to the guy who asked this black light question and the guy whos post i read about dumping a bunch of vinegar in his soil to lower the pH, killing kis plant... duh... damn guys read some shit for a little bit, do some research, if you have to ask these questions not only should you not be growing, you shouldnt have a drivers license or be able to leave the house without a helmet. thank you that is all.
     
  12. i heard during the dark cycle, and drying black lights can help

    try it and see what happens?
     
  13. It will only work is the light is black tho, not that purple bullshit they call black light.;);)
     
  14. #94 mind_loss, Jan 17, 2009
    Last edited by a moderator: Jan 17, 2009
    ok i was reading this post so i had to reply with some studied knowledge.

    i have grown plants with blacklights and i still am. i started because i read this little table that explained alot to me.

    How the Sunlight Effects cannabis plant Growth

    200 - 280 nmUVC ultraviolet range which is extremely harmful to cannabis plants because it is highly toxic.

    280 - 315 nmIncludes harmful UVB ultraviolet light which causes cannabis plants colors to fade.

    315 - 380 nm>Range of UVA ultraviolet light which is neither harmful nor beneficial to cannabis plant growth.

    380 - 400 nm>Start of visible light spectrum. Process of chlorophyll absorption begins. UV protected plastics ideally block out any light below this range.

    400 - 520 nm>This range includes violet, blue, and green bands. Peak absorption by chlorophyll occurs, and a strong influence on photosynthesis. (promotes vegetative growth)

    520 - 610 nmThis range includes the green, yellow, and orange bands and has less absorption by pigments.

    610 - 720 nm<This is the red band. Large amount of absorption by chlorophyll occurs, and most significant influence on photosynthesis. (promotes flowering and budding)

    720 - 1000 nmThere is little absorption by chlorophyll here. Flowering and germination is influenced. At the high end of the band is infrared, which is heat.

    1000+ nm death.


    Between the areas marked(with at<or>) are where the plants grow best.

    band area between 380-420 is where the UVA spectrum is ending and is where i use the black lights till i feel like getting buds. Usually i plant mine indoors after the harvest season of out doors, then when late april- early may comes i move out doors and transplant. and thats that. also i have one plant that has grown up to 3 feet in veg. stage just by using a few UV lights. and i trying a new experiment where i am going to keep a single plant growing under the black light for as long as i can ( trying for atleast 2 years).
     
  15. if your device is emitting 1000+ nm elcmgntc energy then you have bigger issues than plant death, like leaking microwave radiation all over your house and grow space.
     
  16. no that is the whole light spectrum.

    and the 380nm-500nm is where uva lights work.
     
  17. Why do so many people post before doing any research on the topic they are asking about? everyone wants a hand out. well this is what i have to say to those people...:poke:(pokey, pokey, pokey)
     
  18. why is this stickyied?
     
  19. we all should let him find out wether it work's or not
    as the saying is " you learn from your mistakes "
     
  20. we just started flowering 2 plants with a 1000 hps. my roommate has a blacklight in with the plants at night bc he thinks it will create extra thc production. is this harming the plants at all? also, the way we have the room setup, we have allowed light to enter during the dark period. its just a little light contamination but still. any advice?
     

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