12/12 18/6 Who decided that???

faller200

Well-Known Member
I guess I'll throw my answer into the ring...People have chosen to use these times "18/6 and 12/12 because trial and error (which has been pointed out by many on here) has proven good results for most strains...Reason being your growing indoors...now once you accept that, you should know there's no possible way to really mimic outdoor style growing...The benefit of growing indoors is to create your own personal environment (however lighting cycle you choose, co2 you choose, nutrients etc etc...) getting back to the point here...these times are great because of the fact that you could never get sunlight for 18 hours outdoors, thats the whole point here, indoor growing is all about creating the most beneficial environment for the plant. Thus giving a plant more light than it could ever get..you'll never get 7 to 9 weeks of straight sunlight outdoors either lol...the 12/12 is a consistent light dark period to control exactly how your plant is going to be forced into flower and stay that way..sure you could give a plant 11 or ten of darkness but that will force maturity to the buds. Another quick point (tired of typing lol) is 18/6 after trial and error "which is in most grow books as facts" is the best ratio of light to dark to get the best root system...which in my opinion is by far the most important factor towards a plants health, size, and ending yield... 24/7 your plants will grow fast and lush but with the least amount of root growth, 18/6 will give a decent speed of foliage growth and root system, while 16/8 will give the most roots but a smaller foliage...at the end of the day its ALL about your own personal grow space and what your trying to achieve with what you have to work with....
Hey thanks for the civilized answer and one that did not contain the word NATURE I "m with you on 24/7 for veg. It's too much. I have been using 14/10 for veg for awhile now and I do notice slower growth as far as foliage but much better roots. I also see lower dark time temps due to an extra 4 hours of dark.
 

faller200

Well-Known Member
Im doing a 7/12 light cycle to force the plant to finish faster(in theroy a 8 week strain should finish in 6ish weeks) I know yield will be affected but hey I like to experiment
I'm with you buddy. You think out of the box as I do. Here is a light cycle to try some day for flower use 14/14 or 18/14 and see what happens "Peace"
 

ULMResearch

Active Member
I'm with you buddy. You think out of the box as I do. Here is a light cycle to try some day for flower use 14/14 or 18/14 and see what happens "Peace"
It took you this long to get it.. amazing! But at least you finally understand, even if you don't realize it.

18/6, 24/0, 12/12 all came about because people did what that guy is doing. They tried it. When you couple that with theories, recording data, observing results and studying all the material you have just done... SCIENCE!
 

supersillybilly

Well-Known Member
My experiment is just to fool the plants into shorter days. 7 hours of light and 12 of dark. Messed around with my head when I was trying to set the timer.lol I'm not sure if it will work, but if it does I'm going to be doing a more controlled experiment. ie Clones and compare with a 12/12 grow.
 

Cococola36

Well-Known Member
Hey thanks for the civilized answer and one that did not contain the word NATURE I "m with you on 24/7 for veg. It's too much. I have been using 14/10 for veg for awhile now and I do notice slower growth as far as foliage but much better roots. I also see lower dark time temps due to an extra 4 hours of dark.
not a problem, i love to see people try new things, because I'm too scared to try them lol....and when i see new tricks of the trade that work i don't mind using them ;)
 

faller200

Well-Known Member
My experiment is just to fool the plants into shorter days. 7 hours of light and 12 of dark. Messed around with my head when I was trying to set the timer.lol I'm not sure if it will work, but if it does I'm going to be doing a more controlled experiment. ie Clones and compare with a 12/12 grow.
I know I'm going to start more controversy with this but I love it. LOL I may be wrong here but I have read that it's not the length of daylight that makes a plant flower it's the amount of uninterrupted darkness. I am sure your experiment will work
 

Vumar

Well-Known Member
The amount of uninterrupted darkness triggers a chemical (or hormonal? Cant remember... think chemical) reaction within the plant, I read it once. Seriously.
 

ULMResearch

Active Member
It's a hormone. There is a hormone that breaks down in the absence of light and it takes a certain amount of darkness for it to occur. Once the hormone breaks down it gives the plant the signal to flower. If it starts getting light at night eventually the original hormone will build up and the plant will be signaled to perform vegetative growth.
 

stinkyg

Well-Known Member
GOD!!!!!!!!! or someone or something equally as heavy ! 24 hrs in the day normal light cycle. its been tested before numerous times and 18/6 n 12/12 work best. me personally ive done 24on/0off and ive done 10on/14off. 24/0 dont seem any better than 18/6 and 10on/14off and buddage suffers a bit. i keep with the usual now !
 

stinkyg

Well-Known Member
your right it is dark not light that triggers the flowering mechanism, "mechanism" sounds fookin bionic !!
 

stinkyg

Well-Known Member
hmmm ive read most of these posts and im intrigued to say the least ! go on faller200 show us.... if it works you might just be on to something. less hrs of light does equal less bud though .
 

suTraGrow

Well-Known Member
less light = less photosynthesis.
It will work and has been covered by a lot of authors already such as Greg Green, Jorge Cervantes, Ed Rosenthal etc...anything under 13 hours will flower and 14 hours will keep you in veg. But you will be adding a lot of time into the flowering period resulting in running your lights even longer and you might even end up paying more.

Marijuana Horticulture the indoor outdoor growers bible by Jorge Cervantes
The Cannabis breeders bible by Greg Green

there ya go buddy sometimes you have to pick up a book and not just use the internet for everything ;)
 

faller200

Well-Known Member
OK it's been a full cycle of veg at 14/10 and flower at 10/14 and I have my results. (your results may vary LOL)

Veg: Very slow growth at 3 weeks this strain started to flower. 14/10 did not work for me.

Flower: I got some of the results I was looking for. I got shorter plants with tighter branching and much more bush like. They did not out grow the height limit I have. That's a big + Now on the down side they took a few weeks longer to finish as someone said they would. So no I did not save anything on elec. The biggest plus was that my yield was fantastic. 6oz off one plant. The best I have done in DWC to date with this strain It's just some good bag seed
 

GunRunner

Active Member
Just because 18/6 doesn't exist in nature other than on the polar ice caps (where MJ doesn't grow) doesn't mean we cant replicate these conditions indoors in a controlled environment in order to grow some plants.

How did people arrive to that magic number? 18/6 - 12/12 - whatever....well it's called experimenting...all scientists do it in order to come up with the best methods.

Go read a few books on the subject.

Seeing from your signature I deduce you're one to complicate things, well chill man, have a Jay, it ain't rocket science unless you want it to be ;P
 

echlectica

Well-Known Member
To answer your question these cycles have been developed by the hundreds of thousands of growers who came before YOU. What your doing is nothing new. I can tell you what will happen now: they will mature faster and have lower yield and lower potency. Latitude is the deciding factor in nature to dictate diurnal rhythms. Indoors we are not really so much trying to approximate the outdoors as to create the optimal conditions for the plant. Right now at my latitude the sunlight is just about 12 /12, if I'm not mistaken the outdoor folks are finishing up right now. .:)
 
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