do you turn the lights off when you veg?... And if so, how long?

[Seamaiden]

Or, we can accept the science that's already been done. Just a thought. :)

 

[DO IT]

I think any1 that veg's under 24/7 should try it themselves. Start going to the gym and working out hard and drink the best supplements but don't sleep just stay up 24/7. I don't think you will see much growth just a lot of stress. I run 18/6 and will start an experiment. I will measure the grow during the 18 hour on time as opposed to the 6 hour dark period and see where I have more growth. I know when I switch my girls to 12/12 is when I have the most explosive growth.

 

[Beastgrow]

I wouldn't see why plants need to rest... Therefore it is a safe bet to just give them maximum amount of energy to allow them to complete their phase... 24 hours for veg, and 12 for flower.... same reason you don't do 10 hours of light for flower is the same reason you don't do 18 hours of light for veg.

 

[Beastgrow]

I think any1 that veg's under 24/7 should try it themselves. Start going to the gym and working out hard and drink the best supplements but don't sleep just stay up 24/7. I don't think you will see much growth just a lot of stress. I run 18/6 and will start an experiment. I will measure the grow during the 18 hour on time as opposed to the 6 hour dark period and see where I have more growth. I know when I switch my girls to 12/12 is when I have the most explosive growth.

You're comparing a human being to a plant. Good game, sir.

 

[moodster]

24/7 all day if you having to turn the veg lights off to save electric " You are doing it wrong " LOL

 

[DO IT]

We breath we eat we grow(when we rest) :-)... maybe a comparison with a rock would of been better. the only thing I know for sure is the most explosive growth I see is when my girls get 12hrs of sleep.

 

[Seamaiden]

So, here is a previous discussion about this. The 10th post has a link to another forum which had a heated argument on the subject.

As a neutral observer, it seems to me like the majority of the science falls on the side of plants prefering a dark period in the photocycle in veg, as long as they are getting as much light as they need. So if you are vegging under weak light the more hours of light the better, but if you have sufficient light for your plants to get their needs met, its best to give them some time off so their metabolic needs get met.

https://www.thcfarmer.com/community/threads/lighting-schedule-during-veg.35581/

Well, Ne, you tried. In the meantime, I'm going to QUOTE good ol' spurr's post here (found on ICMag).

I think people use light on 24/7 because they want to (unwittingly) grow less healthy plants; plants that do not have as high of a rate of photosynthesis and rate of growth as plants using proper diurnal (daylength) time, ex. 20 hours max. Plants use night time even in veg to carry out "light independent reactions" (formally termed "dark reactions") such as calvin cycle, circadian rhythm, etc.

Plants grow the most during the night and very early morning hours...by far.

That said, plants can do without a night time, but it's not a great idea.

Not using a night hinders most plants and shows how much cannabis book authors do not understand plant physiology and photobiology. It's really a shame that the likes of Mel Frank, Ed Rosenthall, Jorge Cervanties, etc., perpetuate the incorrect claims that plants do fine when they don't have night. That claim is total BS in terms of rate of photosynthesis, rate of growth, level of plant stress, calvin cycle, circadian rhythm etc., etc.

Plants need night time for the best growth. Plants can grow without a night but they have reduced rate of photosynthesis, reduced rate of growth, reduced carbon assimilate and partitioning, etc., etc., et al.

Also, Ca is transported within plant (xylem) most efficiently during the night IIRC.

Another issue with providing light 24/7 is "photoinhibition" of plants. The problem is the "Daily Light Integral" (DLI), which is the total amount of light (i.e. photons within PAR range) that irradiates the plant per day (as moles/area/day). Too much DLI is just as bad as too much light (as a single instance measurement with Lux, PPFD (umol), etc) in terms of hindering the plant's biological process. Namely by reducing stomatal conductance that in turn reduces the rate of photosynthesis, Co2 fixation, calcium and boron movement into roots, etc.

DLI is a very important factor and one that is lost on most people, sadly. Lumens, lux, umol (ex as PPDF; Photosynthetic Photon Flux Density), etc., are single instance measurements of light. However, we need to consider the sum of light over the whole day, not just for a second. In other words, we should not be using lumens, lux, PPF (umol/second), umol/area/second, etc., to judge how much light is good for plants unless we only give them a second of light per day. We should be using umol/area/second-DLI, e.g., PPFD-DLI. And while on this topic, we should not use lumens or lux anyway, they are not for plants, we should use at least umol as PPF and as density with area figured in.

FWIW, here is something I wrote last week about ideal PPFD for cannabis adjusted to a natural diurnal bell-curve of PPFD found in nature:

"Control red to far-red light ratio to limit stretching"
https:// www . icmag . com /ic/showthread.php?t=194053

^^ Remove the spaces to view the thread spurr linked.

addendum:

I have tested 24/7 of light when I was new to growing over 15 years ago due to book by so called cannabis gurus. I have also tested it a few years ago. The thing most people don't realize is you can't just look at the plants to judge if 24/7 is better than 16/8 or 17/7. You need to quantify the rate of photosynthesis, rate of Co2 fixation, etc. I find it odd that only at cannabis forums and books would such a silly notion be promoted.

I sickens me how little science is used by cannabis gurus, and because of their status other people assume they are correct, even tho they are not, and those other people perpetuate the incorrect info as is happening in this thread.

@ all:

Either trust me, or study plant photobiology and plant physiology to come to the same conclusion that I have posted: C3 plants need night to grow the best.

More than 18 hours of light a day can be too long of day; over 20 hours is definitely too long. This topic has been studied ad nauseum by plant physiologists and plant scientists of other fields.

 

[Beastgrow]

there is a transition period after you switch to 12/12 that is referred to as "the stretch" and lasts a couple weeks before heavy budding begins.

 

[Mr_GreenGenes]

Ive run both 18/6 and 24/7. Only thing I noticed was a difference in growth and them growing a lil faster under 24/7 light. I think Spurr is a firm believer in what hes sayin, just as I am firm believer that whats hes sayin is BS. Like he said there are lots of books out there with misleading or just plain wrong advice or advice that may be good for some but not for others. Same thing with all the scientific BS thats thrown around all the time.Much like the VPD bullshit. It looks good on paper and def makes for happy plants early in flower but aint worth a fuck if you've got heavy, thick, dense buds unless you want the brown budrot shit stripe running down the middle of your buds IMO.
Everybodys grow is different and we all find that different things work for different folks. I hate to see peeps posting shit like spurr has, downing a method that myself and many others have used for years and have found it to grow some outstanding plants just b/c some fucking book says so. MGG

 

[DO IT]

My tree's usually double or triple in size when I go from 18/6 to 12/12 depending on the strain. I will post a pic of 1 of my bloom rooms that I have 2 different strains in so you can see the difference in strech.

 

[Mr_GreenGenes]

Do It you're comparing apples to oranges. The discussion here is recommendations on running your lights in veg, not how much of a difference you see when you flip and they start the stretch. MGG

 

[DO IT]

Hey thanks for pointing that out :-)

 

[Seamaiden]

Ive run both 18/6 and 24/7. Only thing I noticed was a difference in growth and them growing a lil faster under 24/7 light. I think Spurr is a firm believer in what hes sayin, just as I am firm believer that whats hes sayin is BS. Like he said there are lots of books out there with misleading or just plain wrong advice or advice that may be good for some but not for others. Same thing with all the scientific BS thats thrown around all the time.Much like the VPD bullshit. It looks good on paper and def makes for happy plants early in flower but aint worth a fuck if you've got heavy, thick, dense buds unless you want the brown budrot shit stripe running down the middle of your buds IMO.
Everybodys grow is different and we all find that different things work for different folks. I hate to see peeps posting shit like spurr has, downing a method that myself and many others have used for years and have found it to grow some outstanding plants just b/c some fucking book says so. MGG

It looks as though your experience with the concepts put forth by the "BS" science and spurr are not at all similar, however, that doesn't make it any less valuable or true in a very real sense.

I'll be the first to say that it's as much an art as a science, but I personally will always go first with the peer-reviewed, repeatable experiments that have been being done for far longer than I've been growing weed or anything else for that matter, and last with the word-of-mouth methods I see on canna-fora so often. I don't know if you'd find this of any interest, but damn near all my problems have been solved by going outside the cannabis world for information. I take information found that is regarding other plants (milk being used for control or eradication of PM; my first and only issue with what turned out to be Septoria, aka black spot, was something no one on the cannabis boards could figure out, I did by going to university sites, ag sites, county extension--all are based on hard science and multiple field observations) and then extrapolate that to Cannabis.

As for the vegging photoperiod thing, I've done both methods (and then some!), and haven't found that keeping the lights on for the full 24hr photoperiod is helpful or beneficial to anyone except PG&E. Turns out that the science backs me up. Now what? I've also never had buds go moldy simply due to high RH, again, now what? You say that you and others do better using 24/0. There's the art, even if the science isn't backing it up.

I have also greatly improved plant health by paying closer attention to VPD parameters, both temps and RH.

I'm not saying you're wrong, but I am saying that to call spurr's stuff, the science that he readily shares/d, etc, BS is. :) :)

 

[Confuten1]

I use to run 24/7 veg but have switched to 18/6. Plants seem happier and healthier.
On a side note Ive never seem more growth (several inches) then when i give the plants a 24 hr dark period inbetween veg and flower change. It is comparable to the 4-7 days before i give that dark period.
Confu.

 

[Mr_GreenGenes]

It looks as though your experience with the concepts put forth by the "BS" science and spurr are not at all similar, however, that doesn't make it any less valuable or true in a very real sense.

I'll be the first to say that it's as much an art as a science, but I personally will always go first with the peer-reviewed, repeatable experiments that have been being done for far longer than I've been growing weed or anything else for that matter, and last with the word-of-mouth methods I see on canna-fora so often. I don't know if you'd find this of any interest, but damn near all my problems have been solved by going outside the cannabis world for information. I take information found that is regarding other plants (milk being used for control or eradication of PM; my first and only issue with what turned out to be Septoria, aka black spot, was something no one on the cannabis boards could figure out, I did by going to university sites, ag sites, county extension--all are based on hard science and multiple field observations) and then extrapolate that to Cannabis.

As for the vegging photoperiod thing, I've done both methods (and then some!), and haven't found that keeping the lights on for the full 24hr photoperiod is helpful or beneficial to anyone except PG&E. Turns out that the science backs me up. Now what? I've also never had buds go moldy simply due to high RH, again, now what? You say that you and others do better using 24/0. There's the art, even if the science isn't backing it up.

I have also greatly improved plant health by paying closer attention to VPD parameters, both temps and RH.

I'm not saying you're wrong, but I am saying that to call spurr's stuff, the science that he readily shares/d, etc, BS is. :) :)

Well it didn't seem like he had any prob callin out others' ideas and experiences as BS...now what? Im glad to know you agree with his views and have had good experiences with running your lights 18/6. I personally have found different in my setup. I'd imagine what type of lights being used might have some impact on differences between what people see running 18/6 as opposed to 24/7 as well as other factors. But theres one of the probs with one person dictating whats right or whats best for everyone. Everyones systems/setups/environments are different, as will the results from those be.

Im glad you've found whats best for you concerning how long to run your veg lights. And Im really glad you haven't seen any probs with high RH and budrot late in flower as its a real pain in the ass. I've seen different hence my opposing views. Maybe instead of calling others out as BS spurr could have just pointed out what his opinions are and the science behind them. I aint buyin anything from someone who tells me to NOT look at the plants when deciding if 18/6 or 24/7 is better for the plants.....well I don't know a better indicator or better way to tell if one is better than the other than to look at how the plants react and grow. All the other shit he mentioned is again just BS if the plants are growing faster and are just as healthy. Now what? MGG

 

[Topofthecrop]

I was told once that grass (that you mow) grows at night. Not sure how true it is but i found it interesting non the less. I have my T5 at 18/6.

Found this on another rando site.

"Although grass needs energy from the sun to grow, it does not stop growing at night. It uses the energy it gathered from the sun during the day to make sugars, and actually grows most just before dawn."

Read more: http://www.ehow.com/facts_7950074_grass-grow-night.html#ixzz2gV4yuFpJ

 

[Topofthecrop]

You're comparing a human being to a plant. Good game, sir.

Humans are very much like plants. It's basic micro biology.

 

[Beastgrow]

Humans are very much like plants. It's basic micro biology.

Find a reliable source that says plants need to "sleep"

 

[DO IT]

Don't do it totc don't you compare... :-) here's 1 interesting article I found.

http://news.discovery.com/earth/plants/plants-do-math-to-survive-the-night-130624.htm

 

[DO IT]

Here you go BG....