Lighting schedule during veg.

[Ne Obliviscaris]

I've always run 24/0 during veg as I always thought more time with light, more growth, but I was recently told by a friend that he sees absolutely no difference in total growth over time running 18/6 vs 24/0. I'd obviously prefer to run the lights less and save on my electricity bill, but I find it hard to believe that you really don't get added growth for the extra 6 hours of light. Any input?

One other thing I might as well bring up in this thread. Although I run 24/0 as a rule, I turn off the lights for an hour a couple times a week after I do foliar applications of neem oil so I dont burn the leaves. I don't do this on any set schedule. Any chance this is causing stress to the plants?

 

[hiboy]

Yes you can cut your hours down, though some strains flower easier than others. So you have to keep an eye of em. I would go 18 on minimum.
hiboy

 

[Indicas4me]

Well i run 24/0 from seed to stop stretch immediately.But they will actually grow a little faster with a dark cycle,but it is a stretchy growth.I would actually run them with a dark cycle for veg after stopping initial stretch from seed,but dont mess with a timer.

 

[Cartoon Head]

I`m sure I read somewhere that something important happens on the dark period,like root growth or something but I can`t 100% remember if it`s roots.

 

[Ne Obliviscaris]

OK, thanks for the advice guys, switching to 18/6 tonight. Do they flip more slowly when theres a less drastic photoperiod shift (18/6 to 12/12 as opposed to 24/0 to 12/12)?

 

[smokestack23]

There's been a lot of "discussion" on this topic lately. I saw some studies a guy listed. They prove that plants do better with a dark cycle.

One "debater" kept insisting that he didnt care about science or studies but rather, what he saw with his own eyes and his plants grew better on 24/0 !.

Well it turned out that he should have had a lot more light in his room. The way the studies explained it..in laymans' terms was..
Plants need..or can use a certain minimum of light "energy" per day. Let's say it's 1000..ummm...lolis or some stupid made-up word.
That one guy was giving them less than the minimum in 24 hours because of his shitty lighting. If he had given them the required 1000 "lolis" in a day (24/0) he would have achieved even better growth.
Had he supplied the 1000lolis in 18 hours and given the plants a dark cycle of 6 hours, they would have done better yet.

So the moral was..it IS beneficial for plants to have a dark period..as long as they're getting the required amount of light energy in the cycle. A plant that receives 1000lolis on a 24/0 schedule wont do as well as the same plant that gets 1000lolis and a dark period in one 24hr day. Now whether it's 20/4, 18/6...I dont remember reading anything concrete about that.

 

[Ne Obliviscaris]

There's been a lot of "discussion" on this topic lately. I saw some studies a guy listed. They prove that plants do better with a dark cycle.

One "debater" kept insisting that he didnt care about science or studies but rather, what he saw with his own eyes and his plants grew better on 24/0 !.

Well it turned out that he should have had a lot more light in his room. The way the studies explained it..in laymans' terms was..
Plants need..or can use a certain minimum of light "energy" per day. Let's say it's 1000..ummm...lolis or some stupid made-up word.
That one guy was giving them less than the minimum in 24 hours because of his shitty lighting. If he had given them the required 1000 "lolis" in a day (24/0) he would have achieved even better growth.
Had he supplied the 1000lolis in 18 hours and given the plants a dark cycle of 6 hours, they would have done better yet.

So the moral was..it IS beneficial for plants to have a dark period..as long as they're getting the required amount of light energy in the cycle. A plant that receives 1000lolis on a 24/0 schedule wont do as well as the same plant that gets 1000lolis and a dark period in one 24hr day. Now whether it's 20/4, 18/6...I dont remember reading anything concrete about that.

Thanks, man, that makes complete sense. My veg room is a 2x3 tent and I'm running a 400w ballast with a MH bulb, so I'm guessing I'm well above the daily number of "lolis", which is actually called the "Daily light integral" and is measured as the number of moles of light per day according to:

http://www.cornellcea.com/Horticultural information/light.html

They don't say anything about there being a ceiling on the quantity of DLI that is usable, however. Can you link me to the sources that stated that, or the thread where it was discussed?

Thanks.

 

[freegrow]

yeah ?

this has been a tennis match I've seen go from side to side over and over ....seems to me close to nature is best but no one has put up pics this one is on 24/0 and this one is on 18/6 same strain same watt light yall know side by side comparison to show the science of it ......hum seems to me its one of those each to his own type things dont know for sure some one pics please
:evilgrin0040:

 

[smokestack23]

I'll try to find that info. It was endless. So many links to university studies and scientific jargon. It was pretty funny cause the "smart" guy kept trying to explain endlessly to the guy who believed his own eyes the principle behind it and neither would have it. It was like...here, check out this study..and then he would explain it AGAIN..and dude would go...Take your fuzzy science and shove it...I saw it for myself with my .2 watt battery powered watch screen as lighting...and the science guy would again link to another study and re-explain the principle.....

As for pics or side by side...I'm sure they exist but it would be from a lab I guess. It would be pretty hard to simulate EXACT conditions in different rooms under different bulbs different everything...not like trying two different things in the same room...but I dunno...I'm not debating whether or not it could be done. It could.

Anyway...I'll go take a look-see.

 

[smokestack23]

Pretty sure this is the thread where the two duke it out. If you can get past that you'll find a lot of links and studies linked to from this 42 page thread. Good luck :)

EDIT: oops...maybe I should add the link:
https://www.icmag.com/ic/showthread.php?p=3996203#post3996203

 

[Rugerbaby]

18/6 ftw!

 

[jkjay]

Could keeping the mothers under 24/0 create enough stress to induce male flower growth?

 

[motherlode]

Could keeping the mothers under 24/0 create enough stress to induce male flower growth?

if 24 hours on is enough stress to make a plant hermie it shoud get tossed

 

[jkjay]

Thats what I did, cut down all my TGA projects.

I'll definatly stick with something more like 18/6 in the future anyway.

 

[DBrook420]

I have a degree in Horticulture and I can tell you for sure that a 24/0 photoperiod is not necessary.
Cannabis is what is known as a long night plant. This means they begin flowering when they receive less than a critical amount of radiation. This critical amount is entirely dependant on strain - usually determined by the geographical origin of the strain. What must also be understood is that generative/vegetative growth is initiated by the duration of darkness. As long as plants are not exposed to this critical consecutive duration of darkness, you will keep your plants in veg.
***Through a common practice of night interruption, growers can keep their plants in veg by simply turning lights on for a couple hours during the night to interrupting the duration of darkness plants receive.***
***This generative/vegetative response has nothing to do with light intensity, but spectrum. The red spectrum of a 25watt incandescent bulb would do the job just fine.***
You can save huge money by even just switch over to incansesant bulbs to maintain veg. DO NOT USE CFLsthese emit a blue spectrum which is not conducive to the photoperiodic response you desire.
Your limiting factor here is what type of photosynthetic lighting you use. Your plants need enough energy to grow big and strong. By increasing your wattage, and lights that focus on the blue, red and far red spectrum, you can reduce the amount of time you need to run them. Also, you can supplement with cheaper lighting for at least 8 hours a day which will save you HUGE

 

[claudacio]

I just started running a night interruption type of veg indoors called the gas lantern method or the 12-1 method. 12 on/5.5off/1on/5.5off and then 12 on again. I started doing it because I think my power consumption for the day is too high running a veg tent on 20/4 and a large flowering tent on 12/12 (actually its on 11/13, the flowering half of the 12-1 method), my a/c would run for that 6 hours of over lap just killing me as far as the electric bill. Now I can run my veg tent opposite my flowering tent never really creating a huge draw at any one point during the day, I can spread it out better. Since I started to try this method out I managed to chop my E-bill down over $100-125 for the half the month or so I've been using it.

Also, you initiate flowering by starting at 11on/13off, from there dropping 15minutes every week until you get down to 9on/15off and stay there for the rest of flowering however long that particular strain takes.

I cant say how its going to work out in the end, I've heard a few people say they noticed a 10% loss in yield, or a little bit, but I think a 10% loss in yield can be a fuck up or stress out anywhere along the line. You do end up cutting some time off the overall time in flower, most people say in between a week to 2 were shed, making it possible to squeeze in an extra harvest a year indoors.

My personal opinion, if you have no worries about power companies helping out leo with smart meters and all that shit, than stick to 18/6 or your preferred method of veg, but you can cut power costs/usage by at least 30-35% I would guesstimate so far but I still havent gotten a full months bill by doing it yet so I'll see exactly how much I cut it down next month.

Obviously I have to run this sch. for a while before I can say anything else other than it works, doesnt cause hermies if they werent there already, flowering is initiated faster (with the strains I'm using anyhow), and it saves on electricity. Does it produce the same tasty product....I dont know yet and I'm gonna wonder until I puff some of my current harvest coming.....

 

[motherlode]

gaslight method

well never tried it - still makes sense that you would lose some weight because of the shorter flower period

I use 11/13 the last few weeks of flower to promote them to finish up nice

but 9-15 seems very counter intuitive to me

also seems like it would be stressful to your plants and possible cause them to hermaphrodite

especially if your not dealing with the most stable genetics to begin with

weird I have never heard of this method until just this week when I was advising a novice grower against doing this

 

[ShutUpDonny]

Who you calling a novice grower ML?! :D

I'm going to start it up again in a few weeks with my new fem Haze seeds. If I get males or hermies this time I'll let people know about it, but otherwise I was psyched with the response. They absolutely exploded once I went from 24/0 into the Gas Lantern, and now that I know how to really take care of my ladies (RH in particular) I'm hoping for great things.

Count me as supporting 12/5.5/1/5.5, though I've yet to try the tapering light down during flower.

Sorry for zombie posting.

 

[motherlode]

lol did I type that out loud

glad to hear its working out for you

 

[philly kush]

I've always run 24/0 during veg as I always thought more time with light, more growth, but I was recently told by a friend that he sees absolutely no difference in total growth over time running 18/6 vs 24/0. I'd obviously prefer to run the lights less and save on my electricity bill, but I find it hard to believe that you really don't get added growth for the extra 6 hours of light. Any input?

One other thing I might as well bring up in this thread. Although I run 24/0 as a rule, I turn off the lights for an hour a couple times a week after I do foliar applications of neem oil so I dont burn the leaves. I don't do this on any set schedule. Any chance this is causing stress to the plants?

I run 18hrs for veg.I feel that they need a dark period as there is one in nature,plants do alot of things in the dark. you wanna make them feel they r in thier natural enviroment.Im far from a pro but this my advice.PEACE!