Light Leaks!!!!!!

thaohaitrieu8

New Member
Joined
Oct 28, 2014
Messages
3
Reaction score
0
Just a reminder for those growers who grow complacent with their rooms tents etc as I did. Check for light leaks every once in awhile. I've been running my Purple Haze for I cant remember how long now and at 6 weeks flower should be looking close to done, but it sure looked funny, like it was trying to reveg on me. I attributed it to heat stress. We have had an unseasonably warm summer here up north. I normally check my room at night but noticed one of my walls had separated a bit and the caulking had come loose this am. Glad I noticed and repaired the problem. Fingers crossed for no herms!
 
Joined
Aug 22, 2006
Messages
19,438
Reaction score
8,313
Revegging is never caused by heat stress. The only thing that will cause revegging is light. So, if your plant is revegging, it IS a light leak or an interruption of the dark in one manner or the other. For instance it is not okay to "just peek into the flowering tent or to do some little tiny chore because you are only going to be a minute or two".

Glad you spotted this and got it fixed. As a side note, you are probably going to want to let your purple haze go 9 weeks or so (more now that you have the reveg thing). Even though only 1/2 haze, those hazes are long flowering strains.
 

zem

Well-Known Member
Joined
Dec 6, 2009
Messages
3,245
Reaction score
614
a light leak is a terrible way to lose a crop. gladly it was always in check wherever i grew. basically i never allow any way for a direct ray of light to enter. sometimes broken light did appear from some edges of the flowering space but as long as it was just a dim light like dimmer than the moon, it never caused any harm
 

DogBoy420

Well-Known Member
Joined
Oct 31, 2014
Messages
45
Reaction score
1
Revegging is never caused by heat stress. The only thing that will cause revegging is light. So, if your plant is revegging, it IS a light leak or an interruption of the dark in one manner or the other. For instance it is not okay to "just peek into the flowering tent or to do some little tiny chore because you are only going to be a minute or two".

Glad you spotted this and got it fixed. As a side note, you are probably going to want to let your purple haze go 9 weeks or so (more now that you have the reveg thing). Even though only 1/2 haze, those hazes are long flowering strains.
I've found that occasional light leaks are not the curse they have been hyped to be.

I'm talking about the myth that 12 continuous hours of ABSOLUTE darkness are required, else hermies result. Not true. If this was true, then the moonlight would hermie every outdoor plant.

Some nights, I can actually read a newspaper outside in the full moon light. Yes I have to squint a bit, but I can still read. Yet my outdoor plants do just fine. And so do my indoor plants, even though I'm less paranoid about light leaks.

I'm not talking about a constant, nightly light leak. I'm just saying that occasional light leaks don't consistently cause hermies in plants with good genetics.
 

zem

Well-Known Member
Joined
Dec 6, 2009
Messages
3,245
Reaction score
614
I've found that occasional light leaks are not the curse they have been hyped to be.

I'm talking about the myth that 12 continuous hours of ABSOLUTE darkness are required, else hermies result. Not true. If this was true, then the moonlight would hermie every outdoor plant.

Some nights, I can actually read a newspaper outside in the full moon light. Yes I have to squint a bit, but I can still read. Yet my outdoor plants do just fine. And so do my indoor plants, even though I'm less paranoid about light leaks.

I'm not talking about a constant, nightly light leak. I'm just saying that occasional light leaks don't consistently cause hermies in plants with good genetics.
the type of light leak is basic imo. broken up light which may appear at the sides of doors is not the same as a crack which allows a direct passage of light to leaves. a crack in the wall which may allow even a small passage of direct light is bad
 

pcduck

Feed the soil, not the plant
Joined
Oct 1, 2008
Messages
14,299
Reaction score
7,286
I'm talking about the myth that 12 continuous hours of ABSOLUTE darkness are required, else hermies result. Not true. If this was true, then the moonlight would hermie every outdoor plant.
Moonlight is a reflection of light, not direct light. The lumens are quite low. As is the light down at the corner low in lumens. Indoor light leaks are quite more often to be higher lumens
 
Joined
Aug 22, 2006
Messages
19,438
Reaction score
8,313
Light leaks can be a horrible problem and they do cause hermies. Like duck mentioned, the moon is not even real light--it is light reflected off the sun and it is about a quarter of a million miles away. Way different than light coming through a door.
 

DogBoy420

Well-Known Member
Joined
Oct 31, 2014
Messages
45
Reaction score
1
Light leaks can be a horrible problem and they do cause hermies. Like duck mentioned, the moon is not even real light--it is light reflected off the sun and it is about a quarter of a million miles away. Way different than light coming through a door.
Light reflected off the moon IS real light. The sun is 93 million miles away. Adding another 500 thousand miles to that (assuming the moon is on the opposite side of the earth) is nothing by comparison. Outdoor MJ plants are given REAL light by the moon almost every night they're alive. A cloud goes by, it gets dark. Clouds clear, and it gets brighter. Noticeably brighter. Some nights are 100% dark, and some are not.

But heck, for all I know, that might be enough to cause some outdoor plants to hermie.

Constant light leaks throughout the flowering cycle do cause plant stress. And sometimes plant stress causes hermies. I agree. But the intensity of the light plays a part, as do genetics.

I've proved to myself that occasional INCANDESCENT light interruptions are not the bane of MJ growing that they've been made out to be. I have my plants in a room closet that is not light-tight. It's close (97%), but it's not perfectly light-tight. So when I first started growing, I obsessed over it and went to great lengths to make sure the bedroom light was never turned on during flowering, put blackout on all the bedroom windows, etc. Then I read a common sense article about this very subject, quit worrying so much, and have yet to see a hermie. Not that I hit my plants during flower with direct GROW lights. Not at all. But I do sometimes turn on the bedroom light for a minute or two here and there, knowing that there is a bit of light leak through the passive intake vents and a bit around the door. No hermies here.

Then again, I only use top-shelf fem seeds with good reputations for not producing hermies.
 

zem

Well-Known Member
Joined
Dec 6, 2009
Messages
3,245
Reaction score
614
tbh i never had a 100% lightproof growroom as my veg chamber is always wall to wall with the flowering chamber and there is always that thin line appearing around the door and where else. I make sure there is no direct light penetrating through any hole or crack, and I yet have to see a hermie. actually the only hermie i saw was outdoor on a plant that was left with very little water or food and neglected, it turned out to be more than just a herm, it was like 1/2 male 1/2 female. theres a pic of it, you can see a top bud forming, with so many pollen sacks around it, it's almost freaky :D

View attachment 073.jpg
 

DogBoy420

Well-Known Member
Joined
Oct 31, 2014
Messages
45
Reaction score
1

Hackerman

Well-Known Member
Joined
Apr 18, 2014
Messages
3,029
Reaction score
272
Interesting paragraph from that article linked above....keeping in mind that cannabis is a short day plant

Some long-night plants (a.k.a., short-day plants) flower most prolifically when grown with low intensity light (approximately 0.5 lux) rather than complete darkness during the night.
 

pcduck

Feed the soil, not the plant
Joined
Oct 1, 2008
Messages
14,299
Reaction score
7,286
What myth was busted?
That the moon does not affect mj.
0.3 lumens :rofl:
 
Joined
Aug 22, 2006
Messages
19,438
Reaction score
8,313
SOME long-nights plants....I haven't found cannabis to be one of them. Plants do hermy because of light leaks and they do have fluffier airy buds if you do not maintain 100% dark. Small continual light leaks does affect budding, but not in a positive way. I did learn this from experience when first growing. A small continual light leak will allow a plant to keep budding....usually, but not always--I have seen plant reveg with very little light. However, even if they do continue budding, the buds are not as tight and dense as plants that I got when I got my rooms completely dark. I am speaking from 30+ years of growing.
 

justafarmer

Well-Known Member
Joined
Nov 14, 2014
Messages
87
Reaction score
1
The following science article explicitly states that moonlight is indeed bright enough to affect some photoperiod plants - yet MJ doesn't seem to be affected.

http://www.howplantswork.com/2009/07/25/does-the-moon-affect-plants-part-2-moonlight-and-biorhythms/

Quit worrying so much about occasional small light leaks from incandescent light bulbs. If you have good genetics and the leaks are kept to a reasonable minimum, your plants will be fine.

Another myth busted...

lol!

how about have your stuff dialed in so that you dont expose the plants to the stress and confusion?????
 
Joined
Aug 22, 2006
Messages
19,438
Reaction score
8,313
After growing for decades and watching hundreds, if not thousands, of grows here and other forums, I KNOW that light leaks do cause problems. There is really no way that I believe this myth is busted. I have seen it happen way way too many times to not know that light leaks cause hermies.
 
Top