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Light leak myth?

Discussion in 'Growing Marijuana Indoors' started by Arcticgrower11, Mar 20, 2012.

  1. I've grown for about two years now and when I receive advice I try to rationalize why it would/ wouldn't work.

    Light leak - generally accepted understanding

    It's common grow knowledge that light leaks cause stress which then causes hermies.

    The myth?
    The basic grow strives to replicate the plants natural outdoor environment (temp, light, humidity, nutrients, co2, etc).

    So how do you account for ambient light during outdoor grows? Moonlight is brighter than common indoor bulbs and I'm supposed to believe that light leak can cause hermies but outdoor gardens are immune to moonlight?

    I don't buy it, its not consistent with the plants natural environment

    Food for thought
     
  2. Ask this in the outdoor section and you will get a ton of replies on how little light if none the plants recieve from the moon. Remember it is light reflected from the sun, not a light source. I can't remember the exact reasoning. Not a scientist, but remember reading it a few times last summer. There are lots of outdoor grows ruined do to street lights, and neighbors.

    I think I remember now but don't quote me on this. The moons light is not in a useable wavelength for plants to use. Kind of like a green light in your grow room.
     
  3. I had a little problem with it with mine. I tried to run my lights at night an off during the day. It wasn't much light but enough. It seem to make the flower slower an finish a little latter. I went back to running them during the day an havent had a problem since. I also do outdoor an I can't really tell the light making a difference. U think like a full moon an a clear ski is hella bright. But out door the timing is not as precise as indoor flower times. This is just what happen to me I am sure other people will say different
     
  4. ^ yeah man a lot of strains will start to flower at anything less than like 15 hrs of light. As we all know there is no day of the year that we get 12/12 outdoors.

    It is totally different outdoors. The sun is a different wave lengths at different times of the year. And different intensities

    To the OP.You are not the first to question the zero light leak rule. And I can pretty much guarantee you won't be the one to prove it wrong. Not trying to be a dick, but this has been played with by many people, and there is a reason everyone says NO LIGHT LEAKS. But it is always good to use your head, and question things.
     
  5. [quote name='"todderfran"']To the OP.You are not the first to question the zero light leak rule. And I can pretty much guarantee you won't be the one to prove it wrong. Not trying to be a dick, but this has been played with by many people, and there is a reason everyone says NO LIGHT LEAKS. But it is always good to use your head, and question things.[/quote]

    Yeah I didn't think I was going to prove/disprove anything. I just thought it didn't make sense if moonlight didn't stress plants why would indoor lights?

    You brought up the wavelength issue before and that's one thing I hadn't considered. It definitely makes sense that the plants can't convert moonlight if it's a different wavelength from sunlight.

    MYTH unbusted!! Or busted!!! One or the other

    Next myth, transplant stress, lol (I have a theory on that if anyone is curious)
     
  6. LOL. I say what the hell is transplant stress. if you get this phenomenon then you are doing something wrong. Just my opinion. My girls never show stress from transplanting. They even show new growth that day.
     
  7. What bulbs are those? A full moon is much, much less light than even a 4w night light. It looks bright to our eyes because of the contrast to the deep black of space, but it isn't giving off much light at all.

    It's true that there is a minimal amount of light that won't bother the plants. However:
    - That amount is different for each strain
    - Whatever it is, it's a lot less than you think
    - You don't have a good way to measure it
    - You use your eyes to measure it, which is not a good way at all to do it (we perceive light, we don't experience it directly the way plants do)
    - If you allow the mindset that a tiny bit of light is OK, then your idea of a tiny bit and my idea are two different things. Plus, once you open the door...people who think a tiny bit of light is OK will soon convince themselves that a tiny bit more than a tiny bit of light is OK, and then a tiny bit more than that is OK, and before you know it everyone is growing hermies.

    Technically you don't keep the dark cycle completely dark because that is the one and only way the plants can handle it, you keep it completely dark because any amount of light represents a risk -- an unnecessary risk -- of ruining your crop. As a practical matter it's the only prudent way to grow.
     
  8. Todder- I agree with you on the stress. I think/thought other growers looked at it as a last resort. I've never had problems.... Maybe a few accidents but not any problems.
    I checked out some of your other posts and that jock looks very good. I didn't spend much time reading the post but I saw you used promix w perilite and worm castings, etc.... I was very close to using promix, the guy at the shop put me on ReadyGro by botanicare. How do you like the promix? I gotta say the botanicare was exactly what I was looking for when I looked to move away from ocean Forrest
     
  9. [quote name='"toastybiz"']completely dark because that is the one and only way the plants can handle it, you keep it completely dark because any amount of light represents a risk -- an unnecessary risk -- of ruining your crop. As a practical matter it's the only prudent way to grow.[/quote]

    I looked up how much light the moon gives off from the suns reflection and it is about 7%. Not that I'm arguing with you. But that seems like more light than a nightlight could give off? I could be wrong though

    Either way you said it best in the quoted portion. I personally use a grow tent to prevent light leaks
     
  10. Thanks toasty. You're always good for the final answer.

    Arctic I use Sunshine mix#4. Basically the same thing as pro mix. No worm castings added to mine. Just straight sunshine,and soul synthetic nutes.
     
  11. I grow in a closet. Because of humidity, I leave the closet door open (except when the landlord is over making repairs once in a blue moon). Day and night, the door is open. I have a light about 8 feet from the closet door. It shines into the closet, every night.

    In several years of growing, I have had exactly TWO hermies.

    Now, either the Ganja Goddess loves me ;), or the "light leak" theory is a bit over-blown! :rolleyes:

    Granny
     
  12. Not even close. Wikipedia info:
    direct sunlight = 32,000–130,000 lux,
    full moon = 0.27 lux (and other moon phases less than that)

    Or from a different page on Wikipedia: the sun is "398,359 times brighter than mean full moon".

    But this isn't a discussion of how bright the moon is, it's about light leaks in the grow space, in which case there are only two conditions for the grower to be concerned with:
    totally dark = safe
    not totally dark = some amount of risk

    Choose wisely.
     

  13. I think the light leak thing is bogus even outdoors we would garden pretty regular at night due too it being so dang hot in the days with extremly bright flood lights and never caused a problem in ten years of outdoor grows in southern arkansas we did this regularly until my uncle turned fuckin snitch cause he got caugt with a small bag and an ratted out the whole grow op i since moved from that shit state and trying my hand and the indoor grow action i dont know if a few hours every other night would really stress it out that bad but thats just my experiance thought i would share it guys:)
     
  14. I think when the earths in rotation uv rays are blocked by the moon but brightens it to our view. its not enough. but light wont only make plants hermie which i havent heard much of. but it will interrupt the flowering cycle causing it to revert back to the vegetative stage, which can cost you weeks and eventually too many times stress the plant out to hermie.
     
  15. #15 GenuineBuddy, Mar 11, 2015
    Last edited by a moderator: Mar 11, 2015
    Sorry but the kelvin temperature of moonlight is the same as sunlight, about 5500k on a clear night, making it a VERY usable wavelength.   It's just exceedingly dim, almost non existent, compared to sunlight.
     
    A full moon shines with a magnitute of -12.7, the sun a magnitude of -26.7 (14 magnitudes brighter), so if we had 398,110 full moons we would have light at night that is the same temperature and brightness as the sun.
     
  16. The best is pictures of the flowering plants in their night cycle

    Sent from my HTCEVOV4G using Grasscity Forum mobile app
     
  17. #17 str8jacket, Mar 11, 2015
    Last edited by a moderator: Mar 11, 2015
    "As we all know there is no day of the year that we get 12/12 outdoors."
     
    Of all the ridiculous and clueless claims made in this thread, that one takes the cake.
     
    The vernal and autumnal equinoxes are just a myth? Bwahahaha
     
    The moon is no brighter than a 4w night light? That's a crock of shit. Try putting a 4w night light out in your yard during a new moon and see if it's as bright as a full moon lit night. What a clueless statement.
     
    Reflected light isn't the same as a 'real source light'? Moon light is not the right spectrum for plants? Those two have to tie for second place in most idiotic claims dept.
     
    Personally, I have never had a light tight flowering room that was totally and completely dark without any light leaks; ever.
     
    I haven't had a hermie since the 80's before I learned to keep plants healthy vigorous and stress free (and before I learned not to flower seed plants before they are mature).
     
    I am currently using a sky light and a window in my flowering room to let sunlight in. There is some light from street lights and stars even during a new moon, and during a full moon when it gets high in the sky I could literally read a book in there if I let my eyes adjust first.
     
    I have always kept a 40w incandescent bulb in my flowering room that I use when I need to do anything in there during the dark cycle, and I have on a few occasions accidentally left it on for days at a time without any issues. A 40w incandescent light puts out way less PAR energy than a full moon.
     
    I've seen a lot of hermies that the growers blamed on 'light pollution', when it was actually due to poor growing skills/practices (pathetic looking plants clearly suffering from stress because someone didn't know what they were doing).
     
    But they'll say it was due to light pollution, and someone else will believe that to be the case, and they tell 2 people and those 2 people tell 2 people and so on, and that's how misinformation spreads so rapidly.
     
    Any time you see someone post that they had plants go hermie, take note on what the plants look like and how soon they were switched to 12/12. Young female seed plants are like teenage girls with raging hormones. Stress causes hormonal reactions.
     
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  18.  
    what sort of device did you use to measure the full moon and your 4w light?
     
    just curious how you came to this conclusion.
     
  19. #20 str8jacket, Mar 11, 2015
    Last edited by a moderator: Mar 11, 2015
     
    We're talking about full exposure to the full moon right? Not just a little of it shining through a small crack?
     
    Are you aware of the inverse square law, and understand how in comes into play with moon light vs a 4w night light? If you put a night light close enough to a fan leaf, you might light up that one fan as much as a full  moon would, but you can't light up the whole plant nearly as much, let alone a whole room full of plants. We were talking about ambient light right? Not strapping night lights to fan leaves.
     
    Do you believe you could light up your back yard with a 4w night light on an extension cord as much as a full moon lights it up?
     
    And that is strictly going by lux/lumen. A 4w night light puts out almost no PAR energy compared to the PAR energy of a full moon.
     
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