# Flowering with 14 hours light



## BobCajun (Nov 29, 2016)

Here's something I found interesting, from this article. It appears that weed can flower under surprisingly long days. The flowering phases were identical with 12/12 and the natural outdoor day lengths which varied from more than 14 to less than 12. This may explain why people have flowered with 14 hour days while using end of day far red treatments. I couldn't find any evidence that such treatments are capable of reducing the number of dark hours required for short day plants to flower, though it was useful for increasing stem length.

It's probably possible to flower with 14 hour days even without any far red treatments and the length of time to maturity may not be that much different from 12/12. Can't really tell from this table because at the end the days are less than 12 hours anyway, but I think it's possible. At least they started flowering and kept flowering at the same rate as 12 hours in the early phases, which is unexpected. Since the table shows that florets formed with 14.16 hours, they must have started being induced a week earlier with 14.4 hours. That particular strain, G5, was a high CBD strain, but it may be similar for THC ones.


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## whitebb2727 (Nov 29, 2016)

I do this. I don't go straight to 12/12. I reduce gradually. Most strains will start flower at about 14-14.5 hours light outdoors and indoor if gradual decrease in time.


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## BobCajun (Nov 30, 2016)

whitebb2727 said:


> I do this. I don't go straight to 12/12. I reduce gradually. Most strains will start flower at about 14-14.5 hours light outdoors and indoor if gradual decrease in time.


Yeah it looks like 14.5 hours is the critical day length, at least for most non-equatorial strains. And notice that there was "rapid formation of new florets " until it got down to 12.56 hours, so might as well say 13 hours. Then at 12 1/2 hours it slowed and at 12 hours it ceased. Maybe we don't want rapid formation to slow or cease. 

Maybe we need at least 13 1/2 hours to keep rapid formation going and then after say 8 weeks we would go down to 12 hours to induce senescence. But the only people who ever tried indoor growing with 14 hours are those who were under the impression that EOD far red was making 14 look like 12 to the plants. That impression was almost certainly false. I guess we'd have to ask one of those people what the results of a 14 hour photoperiod were. The far red obviously doesn't equate to 2 more hours of darkness, because I tried it before using 12/12 and it still took 10 weeks to ripen. It would have ripened much faster if it worked, because it would have been like 12/14.


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## BobCajun (Nov 30, 2016)

Interesting post from another forum;


> "So I know a guy that's been growing indoor and outdoor since about 97 and he was telling me that the past few grows he's been doing 24/0 veg and 14/10 flower. He says the buds are way bigger and much denser and the yield is almost doubled. He said when doing 18/6 and 12/12 he would get a little more than 1.5 lbs per 1000w. He says with this method he's pulling almost 3 lbs per 1000w. Anybody else ever hear anything on this before?" source


Must say, twice the yield does sound appealing. I think I'll stick with 13 though. Kind of a compromise.


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## Eagle-ize (Dec 2, 2016)

In my experiences playing with longer photoperiods in the reproductive (flowering) phase, the longer hours produced a bit more weight with slightly larger buds but it didn't double my yield. They did, however, seem to finish a bit sooner than the plants on the 12/12 schedule. At the time, I had already made the transition to LED so... 

A1000w HID radiates IR light for a short period after it is turned off so maybe we can speculate that there is some correlation there.
There are many studies on EOD IR exposure for plants, however, I have found nothing substantial related to cannabis.

I believe the key to the yield directly related to the amount of total light the plant gets (daily light integral). If IR is stated to have
photomorphogenic influence to promote flowering responses, it may be exactly what the plant needs to counteract the longer photoperiod.
After all, it is what occurs in nature.

Nice find sir! This topic is interesting to me so please share your thoughts.

Cheers!


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## a senile fungus (Dec 2, 2016)

The longest duration of light during flower I've ever done is 14hrs. A couple of my strains started to reveg under 14hrs, so I went back to 12/12 to keep it simple.


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## Eagle-ize (Dec 2, 2016)

a senile fungus said:


> The longest duration of light during flower I've ever done is 14hrs. A couple of my strains started to reveg under 14hrs, so I went back to 12/12 to keep it simple.


Just curious... Did you notice a faster finishing time in 14/10?


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## JDMase (Dec 2, 2016)

a senile fungus said:


> The longest duration of light during flower I've ever done is 14hrs. A couple of my strains started to reveg under 14hrs, so I went back to 12/12 to keep it simple.


Maybe with 14 hours you definitely need the far red? Or failing that 13.5 or 13 hours would still be benefitial when compared to 12/12 in some instances?


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## a senile fungus (Dec 2, 2016)

I didn't notice any significant faster finishing time or growth rates, but a couple of those strains were new to me. 

And I don't necessarily think longer days are that beneficial, this is a long night plant. I've found that shortening my veg daylight times (from 20/4 now I'm at 16/ seems to have a more significant impact on flower onset than longer flowering days. Just my experiences...


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## boilingoil (Dec 2, 2016)

Just from my experience in outdoor growing my plants tend to start flowering around the first week of August at my latitude ( 39.7 degrees) about the same time as my sunrise to sunset time hits the 14 hour mark.
I start my flowering at 14/10 and cut a half-hour every week till 12/12. Never saw a increase with flowering times over a straight 12/12 regime and the extra lighting cost over a regular cycle is around $5 more running 600 watts and i'm pulling close to 2 units from a 4x4 with said 600 watts.


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## JDMase (Dec 2, 2016)

boilingoil said:


> Just from my experience in outdoor growing my plants tend to start flowering around the first week of August at my latitude ( 39.7 degrees) about the same time as my sunrise to sunset time hits the 14 hour mark.
> I start my flowering at 14/10 and cut a half-hour every week till 12/12. Never saw a increase with flowering times over a straight 12/12 regime and the extra lighting cost over a regular cycle is around $5 more running 600 watts and i'm pulling close to 2 units from a 4x4 with said 600 watts.


I may have read that wrong but are you saying you flip from your veg (18/6 or whatever) to a 14/10, reducing to 12/12 and that costs you $5 (per week? In total?) and what was your benefit to doing so? Im confused haha


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## boilingoil (Dec 2, 2016)

JDMase said:


> I may have read that wrong but are you saying you flip from your veg (18/6 or whatever) to a 14/10, reducing to 12/12 and that costs you $5 (per week? In total?) and what was your benefit to doing so? Im confused haha


 Yes from 18/6 to 14/10, and that's for a whole flowering cycle cost of extra lighting. I pay less than $.10 a KWH.
I'm pulling almost 2 units from a 600 in a 4x4.


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## BobCajun (Dec 2, 2016)

Eagle-ize said:


> In my experiences playing with longer photoperiods in the reproductive (flowering) phase, the longer hours produced a bit more weight with slightly larger buds but it didn't double my yield. They did, however, seem to finish a bit sooner than the plants on the 12/12 schedule. At the time, I had already made the transition to LED so...
> 
> A1000w HID radiates IR light for a short period after it is turned off so maybe we can speculate that there is some correlation there.
> There are many studies on EOD IR exposure for plants, however, I have found nothing substantial related to cannabis.
> ...


What I'm using now is 13/11. It's been on that for the last week or so. Seems to be working well, a bit more growth than with 12/12. I'm not going to use 14 because I don't think the extra power would be worth it and it's bad enough dealing with the heat for 13. I'll see how this run turns out and report the results. Might drop it to 12/12 for the final week.

About the EOD far red, the main effect is stem elongation. I tried it with an incandescent blacklight under 12/12. The plants stretched like crazy with little branching, which is another effect of the far red, suppression of branching. What it does is mimic dense planting, like in a hemp field. If you've ever seen pics of a hemp field you probably wouldn't want plants like that.

You may be right about the HID putting out far red after it shuts off. MH not so much but HPS you can see the arc tube is red. That may explain why HPS grown plants are stretchy and MH grown ones aren't. It only takes about 1 watt of far red light per square meter to produce the effect so that red glow may very well be supplying it. Since it's only for a few seconds it may only cause a certain amount of extra stretch. Probably pure far red for say 15 minutes would make it a lot stretchier than an HPS.

BTW for those who do still use HPS, it might not be a bad idea to use a red light for 5 minutes after the HPS shuts off. That would counteract any far red from the arc tube glow and also from the actual on state during the full day. Again, it only requires a low wattage. A 13w red "party" CFL would probably do it, if you can't find red LEDs. In theory, you should get much stockier and branchier plants. But come to think of it, the arc tube probably puts out far red at first and as it cools it probably gets down into the red range, so it may already be EOD red. But it may not be long enough. You really need a good 5 minutes straight. Maybe that's why HPS produces kind of stretchy plants but not hemp type stretchy. It may have just enough EOD red from the glow to somewhat counter the far red but not fully.

I just found a page with the red/far red ratios of HPS and MH. Hps is 1.05 (to 1) and MH is 3.8. So that probably explains the plant height difference between them, more blue in the MH may also contribute to that. So it looks like HPS really could benefit from EOD red to counter that high far red content. People currently sell far red lights for EOD far red but nobody sells red lights for EOD red. They missed the boat on that one. You could call it the HPS far red neutralizer. MH style plant growth from HPS lights. It's magic.


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## JDMase (Dec 2, 2016)

BobCajun said:


> What I'm using now is 13/11. It's been on that for the last week or so. Seems to be working well, a bit more growth than with 12/12. I'm not going to use 14 because I don't think the extra power would be worth it and it's bad enough dealing with the heat for 13. I'll see how this run turns out and report the results. Might drop it to 12/12 for the final week.
> 
> About the EOD far red, the main effect is stem elongation. I tried it with an incandescent blacklight under 12/12. The plants stretched like crazy with little branching, which is another effect of the far red, suppression of branching. What it does is mimic dense planting, like in a hemp field. If you've ever seen pics of a hemp field you probably wouldn't want plants like that.
> 
> ...


That was a really good read man, ive got some serious stretch going on with my HPS and they're just looking awful and was hoping to counter act it. Gonna look up some red CFL's now to see if I can improve them and help them get bushier.

I am just starting to finish the flowering on my older ones, using a 100w reptile bulb. Was planning on using that for 10 mins at the middle of their day, it has IR uva and uvb, don't suppose that might help too do you? 1w per square metre would be good too (as I have a 1sqm tent) seen some far red led lamps that are damn expensive though!

Just googled, IR IS far red, right? So I could run my reptile bulb during the day for 10-15 minutes for supposed added trichomes and also after lights out for say the same amount for reduced stretch and flower initiation? Have I got that right?


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## BobCajun (Dec 2, 2016)

JDMase said:


> That was a really good read man, ive got some serious stretch going on with my HPS and they're just looking awful and was hoping to counter act it. Gonna look up some red CFL's now to see if I can improve them and help them get bushier.
> 
> I am just starting to finish the flowering on my older ones, using a 100w reptile bulb. Was planning on using that for 10 mins at the middle of their day, it has IR uva and uvb, don't suppose that might help too do you? 1w per square metre would be good too (as I have a 1sqm tent) seen some far red led lamps that are damn expensive though!
> 
> Just googled, IR IS far red, right? So I could run my reptile bulb during the day for 10-15 minutes for supposed added trichomes and also after lights out for say the same amount for reduced stretch and flower initiation? Have I got that right?


No, you didn't understand what I wrote. Far red, which is not quite IR (which is invisible and produces heat when it hits something), CAUSES stretching. Red, meaning normal red colored light, counters the stretching effect of far red. BTW the far red that plants use, around 730 nm, is visible, just not as bright looking as normal red. Infrared (IR) comes after far red and you can't see it.

So to keep your plants from stretching you need to get a red CFL, usually the only ones in stores are 13w ones, and run it for 5-15 minutes after the HPS goes off.

The thing about 1 watt means 1 watt of actual light output, not 1 watt from the wall. You'd probably need about a 5w light minimum for a square meter but might as well make sure by using a 13w CFL or even 2 or more, whatever you think will cover the area nicely.

The reptile light is only good for UV and a little extra PAR (plant usable light), since they do put out some white light in addition to the UV. I can't see it working as a source of EOD red to reduce stretch though. Just get a separate red light, simple as that. And obviously don't use any far red lights at all. Their only use is to make plants stretchy.


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## JDMase (Dec 2, 2016)

BobCajun said:


> No, you didn't understand what I wrote. Far red, which is not quite IR (which is invisible and produces heat when it hits something), CAUSES stretching. Red, meaning normal red colored light, counters the stretching effect of far red. BTW the far red that plants use, around 730 nm, is visible, just not as bright looking as normal red. Infrared (IR) comes after far red and you can't see it.
> 
> So to keep your plants from stretching you need to get a red CFL, usually the only ones in stores are 13w ones, and run it for 5-15 minutes after the HPS goes off.
> 
> ...


Yeah I re read that, I did wonder why you said that as obviously im running HPS and have stretch haha! 

So which lights are the ones that are flower initiators? I thought those were "far red"? I'll do some more research. But in the meantime.. 

I'll give the cfl a go, thanks so much for your patience and information! Im certainly learning a lot.


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## BobCajun (Dec 2, 2016)

JDMase said:


> Yeah I re read that, I did wonder why you said that as obviously im running HPS and have stretch haha!
> 
> So which lights are the ones that are flower initiators? I thought those were "far red"? I'll do some more research. But in the meantime..
> 
> I'll give the cfl a go, thanks so much for your patience and information! Im certainly learning a lot.


Yeah the "flower initiators" are far red. I don't think they initiate flowers though, just make the plants stretchy. Notice that none of the manufacturers show actual experiments proving that they do what they claim.

Now if anyone reading this has HPS lights and a PAR meter, it would be nice to know what the spectrum of a shut off HPS really is. Maybe it's far red, maybe it's red, we don't know because nobody ever thought to check it with a PAR meter.


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## Eagle-ize (Dec 2, 2016)

BobCajun said:


> Yeah the "flower initiators" are far red. I don't think they initiate flowers though, just make the plants stretchy. Notice that none of the manufacturers show actual experiments proving that they do what they claim.
> 
> Now if anyone reading this has HPS lights and a PAR meter, it would be nice to know what the spectrum of a shut off HPS really is. Maybe it's far red, maybe it's red, we don't know because nobody ever thought to check it with a PAR meter.


The problem with this measurement is that the wavelength of light that we want to measure is outside of the PAR meter's sensitivity range and there fore limited.

An UPRTEK Spectroradiometer may be sensitive enough as I believe it dips into 800nm territory.

Maybe an actual experiment is called for.


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## BobCajun (Dec 3, 2016)

Eagle-ize said:


> The problem with this measurement is that the wavelength of light that we want to measure is outside of the PAR meter's sensitivity range and there fore limited.
> 
> An UPRTEK Spectroradiometer may be sensitive enough as I believe it dips into 800nm territory.
> 
> Maybe an actual experiment is called for.


Yeah I thought of that later, that a PAR meter doesn't actually show the spectrum just how much light energy is produced in the PAR range, which usually stops at 700 NM.


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## Eagle-ize (Dec 3, 2016)

BobCajun said:


> What I'm using now is 13/11. It's been on that for the last week or so. Seems to be working well, a bit more growth than with 12/12. I'm not going to use 14 because I don't think the extra power would be worth it and it's bad enough dealing with the heat for 13. I'll see how this run turns out and report the results. Might drop it to 12/12 for the final week.
> 
> About the EOD far red, the main effect is stem elongation. I tried it with an incandescent blacklight under 12/12. The plants stretched like crazy with little branching, which is another effect of the far red, suppression of branching. What it does is mimic dense planting, like in a hemp field. If you've ever seen pics of a hemp field you probably wouldn't want plants like that.
> 
> ...


I have read that blue light inhibits etiolation (stretching) and my experience with various light sources corroborate this. If the FR light promotes it, what do you think would happen if it is used only after the initial stretch? 

Here is a picture of an experiment I performed with MH and HPS. The MH was on for the first 8hrs of 12/12 and the HPS was on for the latter half. There was a 4hr period where both were on at the same time. At the time, I was still fairly new to growing.


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## BobCajun (Dec 3, 2016)

Okay, looks very similar. I don't know what would happen if you used far red after initial stretch. Maybe foxtailing. I did get a lot of foxtails when I used an incandescent blacklight for 5 minutes end of day before.


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## sallygram (Dec 5, 2016)

I use a far red lamp in my garden, it turns on about 10 minutes before the HPS turns off and stays on for about 20 minutes, I do a 13 1/2 hour light cycle. Any foxtailing that I have gotten I have blamed on other things. The light cycle seem to only take about threedays off the finish time but I have had problems with some strains that seem to be on the verge of finish and start putting out more buds. In that case I put them in the bathroom with a 10/14 cycle and they usually ripen within a few days and the buds are just as big and hard as the ones that I didnt do the cycle on. (got 6 plants in the bathroom now).


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## BobCajun (Dec 5, 2016)

I'm using 13 hours now and it's working great. I know the thread title is about 14 hours but I don't actually want to use that many, or even 13.5. 13 seems just about right. I'm getting noticeably faster growth than with 12. At 6 weeks flower the buds look like 7 weeks with 12.


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## sallygram (Dec 6, 2016)

When I first read about using far red there was someone that claimed to be only giving their plants 8 hours of dark a day and for some reason they used the far red both at the begining and end of the dark cycle. I have not tried to go under 10 1/2 hours of dark but I do have some new lights coming so I may do a side by side grow.


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## JDMase (Dec 6, 2016)

I thought the use of far red( or is it red) stops the stretch? It is to do with when the sun sets and the red wavelengths are the longest and that's what the plant absorbs to know that night is approaching? 

Someone did explain it to me but my memory is awful. 

Growmau5 done a video on his far red and thought it shortened flowering times. 

I think it just makes the plants aware to switch to night sooner. Because doesn't it take them like 1-2 hours to switch to their night routine?


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## BobCajun (Dec 6, 2016)

JDMase said:


> I thought the use of far red( or is it red) stops the stretch? It is to do with when the sun sets and the red wavelengths are the longest and that's what the plant absorbs to know that night is approaching?
> 
> Someone did explain it to me but my memory is awful.
> 
> ...


The THEORY is that far red at end of day = 2 additional hours of darkness. It has never been scientifically proven. What HAS been proven is that it makes the stems elongate as if the plant was in shade and stretching for light. End of day RED light counteracts the stretching effects of far red. And no, it doesn't shorten flowering times like Growmau5 said. I tried it with 12/12 and it still took 10 weeks like always. It also made my plants stretch like crazy, had to cut the tops off.


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## Odin* (Dec 6, 2016)

Pfr (phytochrome far red receptors) are converted to Pr in darkness, or by far red light. So, although far red light hastens the conversion, it is not alltogether the same as an additional two hours of dark as there are other processes that would occur in that time.


All that there is to be gained by far red light exposure is a quicker onset to flowering on the initial "night" of flower inducing "lights out". Beyond that, it's shear redundancy.


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## BobCajun (Dec 6, 2016)

Odin* said:


> Pfr (phytochrome far red receptors) are converted to Pr in darkness, or by far red light. So, although far red light hastens the conversion, it is not alltogether the same as an additional two hours of dark as there are other processes that would occur in that time.
> 
> 
> All that there is to be gained by far red light exposure is a quicker onset to flowering on the initial "night" of flower inducing "lights out". Beyond that, it's shear redundancy.


I've also read that it only tales about 30 minutes for darkness to convert the phytochrome, not 2 hours. It has never been scientifically established how long it takes but in certain experiments I read about they found that it appeared to be more like 30 minutes. So you might gain half an hour but so what? Not really worth the stretching and lack of branching.


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## Odin* (Dec 6, 2016)

@BobCajun That information is incorrect. It takes far longer for the Pfr to convert to Pr. If it only took 30 minutes then flowering would only require 30 minutes of darkness each night. Pfr inhibits flowering, it is the point at which Pfr levels are insufficient to inhibit flowering that the onset of flower is triggered.


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## BobCajun (Dec 6, 2016)

Odin* said:


> @BobCajun That information is incorrect. It takes far longer for the Pfr to convert to Pr. If it only took 30 minutes then flowering would only require 30 minutes of darkness each night. Pfr inhibits flowering, it is the point at which Pfr levels are insufficient to inhibit flowering that the onset of flower is triggered.


Well I meant whatever people think takes 2 hours. Because 2 hours darkness also doesn't induce flowers.


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## Odin* (Dec 6, 2016)

@BobCajun Yeah, all the far red does is hasten the transition of Pfr to Pr. It doesn't hasten the metabolic pathways initiated by insufficient Pfr (to inhibit flowering). It's only on that first "night" that hours are shaved off, after that, the shorter "day" and longer "nights" maintain flower/low Pfr.

It may trigger a more "aggressive" response to flowering by dropping Pfr rapidly and to lower levels in the given time (again, first night).


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## BobCajun (Dec 6, 2016)

Odin* said:


> @BobCajun Yeah, all the far red does is hasten the transition of Pfr to Pr. It doesn't hasten the metabolic pathways initiated by insufficient Pfr (to inhibit flowering). It's only on that first "night" that hours are shaved off, after that, the shorter "day" and longer "nights" maintain flower/low Pfr.
> 
> It may trigger a more "aggressive" response to flowering by dropping Pfr rapidly and to lower levels in the given time (again, first night).


Why would it only work on the first night? It works every night you do it. But I just don't believe it equates to 2 more hours of darkness.


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## Odin* (Dec 6, 2016)

@BobCajun It would only be effective that first night because prior to that it was exposed to long days and short nights. Those long days maintain very high ratios of Pfr to Pr. After that initial "night" (to initiate bloom) the plant(s) will no longer be subjected to such long "days" (unless there is a "fuck up", resulting in "reveg"), as well as longer nights, both fascilitating greater Pr to Pfr ratios. Only in onset would it benefit, after that Pr to Pfr is maintained by the light schedule.


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## BobCajun (Dec 6, 2016)

Odin* said:


> @BobCajun It would only be effective that first night because prior to that it was exposed to long days and short nights. Those long days maintain very high ratios of Pfr to Pr. After that initial "night" (to initiate bloom) the plant(s) will no longer be subjected to such long "days" (unless there is a "fuck up", resulting in "reveg"), as well as longer nights, both fascilitating greater Pr to Pfr ratios. Only in onset would it benefit, after that Pr to Pfr is maintained by the light schedule.


Okay maybe it's like giving them 24-36 hours darkness the first night then. Some people do that. I hadn't heard anything about the first night only, just every night with the EOD far red. Personally I find it doubtful but I guess it's conceivable. Is that what the vendors say about the initiator? Where did you get that from? It doesn't actually say that here. Says every day. I don't believe it works like they say. You can flower with 13-14 hours without the initiator light anyway. Just my opinion, don't know for sure. But what they don't tell you is that the far red will cause crazy stretching and reduced branching. Not really worth it.


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## Odin* (Dec 6, 2016)

The guys trying to sell you a light aren't going to say that it's "essentially useless". The far red every "night" is a gimmick, nothing more. Plenty of info out there on the subject (I've shared some here already).


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## Eagle-ize (Dec 6, 2016)

Odin* said:


> The guys trying to sell you a light aren't going to say that it's "essentially useless". The far red every "night" is a gimmick, nothing more. Plenty of info out there on the subject (I've shared some here already).


Would it be possible to get an explanation on what happens with plants in nature after the sun goes down? Don't they get a daily dose of the far red light too?


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## Dr. Who (Dec 7, 2016)

Eagle-ize said:


> In my experiences playing with longer photoperiods in the reproductive (flowering) phase, the longer hours produced a bit more weight with slightly larger buds but it didn't double my yield. They did, however, seem to finish a bit sooner than the plants on the 12/12 schedule. At the time, I had already made the transition to LED so...
> 
> A1000w HID radiates IR light for a short period after it is turned off so maybe we can speculate that there is some correlation there.
> There are many studies on EOD IR exposure for plants, however, I have found nothing substantial related to cannabis.
> ...


 IR nm bands are not used by plants (760 nm - 1400nm) Far red is what puts the plants to "sleep".....like around 710 -750nm with 730nm being the actual most effective nm band...or at least the one used most......If I remember right it's like plant effective from like 722 to 738nm..in a positive and negative, or "complete" bell curve....

@BobCajun

I got some of those 730nm 10w & 20w "flower initiators" a few years back. I found that the return in gain was not able to cover the cost of use when tied to 2 hrs of lighting increase. I've sold most of them to folks that wanted to try it them selves.....they aren't using them anymore either!

Longer bloom times also cause more unstable plants and in turn more plant problems in bloom then with shorter time like 11.5 to 11 hrs of ON lighting times...This has been proven by folks like DJ Short and others. Plants are more _likely_ to herm with longer lighting bloom times.

I use a diminishing lighting time with high and pure sativa's to get a better and more positive finish.

I find your simply not gaining enough to justify a lighting time over 12/12....


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## Dr. Who (Dec 7, 2016)

Eagle-ize said:


> Would it be possible to get an explanation on what happens with plants in nature after the sun goes down? Don't they get a daily dose of the far red light too?


Exposure of FR in nature, is by very low amounts over an extended period. That period last for _about,_ right before the sun goes over the horizen, to actual complete darkness. About 2 hrs.
That's why 5 - 10 min exposures of the 730nm band will completely shut the plant down and you can have that extra "on light" time.

The plant in darkness undergoes a cellular peptide change that allows the plant to use the intense light of day at it's best ability. Till it begins to slow down that ability by about 30% due to the plant hitting the "light saturation point". It's at this point, that the plant begins to change on the cellular peptide level to "protect" it's self from that intense light of the day.

It actually happens at an earlier time then many people think. The use of "extra" lights on times, _is_ allowing for some recovery of this "lost light effectiveness". Another method of "recovery" of this "lost effectiveness", is the use of Co2! Technically speaking in simple terms. The Co2 allows the plant to operate at that "peak" effectiveness _longer!_ I have found it as more effective in recovering that lost 30+% of the growth, lost to that "light saturation point"....

Yet again, cost effectiveness comes into play and the added things to dial in,,, tend to overweight my need to actually use it...

In the end. NOT using these things and simply dialing in your feed to strain and the spectral use of lighting. Will supply a superior product, with results closer to actual plant potential, with higher quality.......the opposite end of the light spectrum is _*far*_ more important!

Think UV!


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## BobCajun (Dec 7, 2016)

Dr. Who said:


> IR nm bands are not used by plants (760 nm - 1400nm) Far red is what puts the plants to "sleep".....like around 710 -750nm with 730nm being the actual most effective nm band...or at least the one used most......If I remember right it's like plant effective from like 722 to 738nm..in a positive and negative, or "complete" bell curve....
> 
> @BobCajun
> 
> ...


So you didn't notice much increase in yield with 14 hours light? How long did it take to ripen with that cycle anyway, extra week?


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## Dr. Who (Dec 7, 2016)

BobCajun said:


> So you didn't notice much increase in yield with 14 hours light? How long did it take to ripen with that cycle anyway, extra week?


Not enough to justify spending the extra cash on all the electrical. Say around 15+ %. The thing being is that around here. The more elec. you use. The higher cost bracket you jump into,when in a residential use classification. I'm not and it's still too much..
Around that but, not as much as I thought it would...I got only days in difference...

Shorter times are faster, yet once you go below 10/14. You really start seeing reduced yields....


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## BobCajun (Dec 7, 2016)

Dr. Who said:


> Not enough to justify spending the extra cash on all the electrical. Say around 15+ %. The thing being is that around here. The more elec. you use. The higher cost bracket you jump into,when in a residential use classification. I'm not and it's still too much..
> Around that but, not as much as I thought it would...I got only days in difference...
> 
> Shorter times are faster, yet once you go below 10/14. You really start seeing reduced yields....


So pretty much a linear increase, 1/6th more hours equated to about 1/6th more weight, and only a few days extra time to ripen. Sounds like a viable option where people don't have to worry as much about power. So the buds weren't leafy or loose or anything like that?


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## RetiredGuerilla (Dec 7, 2016)

I simulated Alaska's photoperiod in a experiment with a indica. The last 2 weeks the lights were on only 4 hours per day. I kept the lights close and ended up with some unreal smoke with huge trikes. Some white widow fans run them with no light or water the last week forcing the plant to produce more trichomes as a defense mechanism.


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## Olive Drab Green (Dec 8, 2016)

Less light is better for flowering. The flowering hormone is released during the dark period. I flower on 10/14.


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## RetiredGuerilla (Dec 8, 2016)

Nice. I been running 10.5 = 6:30 am - 5:00 pm late fall in the southern USA


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## twostrokenut (Dec 8, 2016)

BobCajun said:


> Here's something I found interesting, from this article. It appears that weed can flower under surprisingly long days. The flowering phases were identical with 12/12 and the natural outdoor day lengths which varied from more than 14 to less than 12. This may explain why people have flowered with 14 hour days while using end of day far red treatments. I couldn't find any evidence that such treatments are capable of reducing the number of dark hours required for short day plants to flower, though it was useful for increasing stem length.
> 
> It's probably possible to flower with 14 hour days even without any far red treatments and the length of time to maturity may not be that much different from 12/12. Can't really tell from this table because at the end the days are less than 12 hours anyway, but I think it's possible. At least they started flowering and kept flowering at the same rate as 12 hours in the early phases, which is unexpected. Since the table shows that florets formed with 14.16 hours, they must have started being induced a week earlier with 14.4 hours. That particular strain, G5, was a high CBD strain, but it may be similar for THC ones.


Inda-gro has been doing the far reds with led for quite a while....their gardens show a marked increase in bud sites as well.

To your point, its my understanding the 730nm far red triggers the phytochrome within seconds rather than a couple hours just going lights off to the dark with traditional PAR used in most of our indoor lighting. Supposedly you can add this saved time to the lights on.

Apologies if this was covered already, I just jumped from start to finish.


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## Odin* (Dec 8, 2016)

I don't have the time nor energy to fully address this, nor do I want to contradict what anyone has said/believes/utilizes, but far red exposure does not extend your lights on period or improve "bloom", nor does suppressing light exposure below 12hrs. 

Many have documented 14/10 grows w/o any/significant far red exposure. This would mean that with the inclusion of far red, one could bloom with 8 (or even 7, given the strain) hours of "night". That just doesn't happen indoors, or in nature (in which all cannabis is exposed to far red). Therefore, "Bogus!".

And, "Yes", bloom is triggered and maintained by the introduction of a critical duration of "night", but it is the energy created and stored during the "day" that powers the machine. Anything less than 12 is running on low octane with high compression. Therefore, "Bogus!".


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## RetiredGuerilla (Dec 8, 2016)

As always with this plant we all love there are variables. In nature during fall depending on latitude the days gradually get shorter. Alaska loses about 6 minutes per day. Kentucky loses 1 or 2. I have noticed far more hermies with 12 or more hour days. Like always it depends on strain and the growers technique. I have grown some hi grade meds replicating the photoperiod of Alaska.


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## Dr. Who (Dec 8, 2016)

BobCajun said:


> So pretty much a linear increase, 1/6th more hours equated to about 1/6th more weight, and only a few days extra time to ripen. Sounds like a viable option where people don't have to worry as much about power. So the buds weren't leafy or loose or anything like that?


Linear, yes...and yes......We actually did use them for a year or so in a commercial op. Located in an old Tool and Die shop. We had no electrical problems there! Commercial rates are lower for high consumption....It ended up we had to open another op as the demand was far outstripping our ability to keep up with that demand for the high CBD strains. We had ourselves (2) and 3 other dispensaries to keep supplied with that and several other high demand strains.

No, not at all. In fact most of your actual yield increase is in density! There is some size increase if your not feeding at the optimal rate. There's that dial in importance again!

Great questions Bob!


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## Dr. Who (Dec 8, 2016)

Odin* said:


> I don't have the time nor energy to fully address this, nor do I want to contradict what anyone has said/believes/utilizes, but far red exposure does not extend your lights on period or improve "bloom", nor does suppressing light exposure below 12hrs.
> 
> Many have documented 14/10 grows w/o any/significant far red exposure. This would mean that with the inclusion of far red, one could bloom with 8 (or even 7, given the strain) hours of "night". That just doesn't happen indoors, or in nature (in which all cannabis is exposed to far red). Therefore, "Bogus!".
> 
> And, "Yes", bloom is triggered and maintained by the introduction of a critical duration of "night", but it is the energy created and stored during the "day" that powers the machine. Anything less than 12 is running on low octane with high compression. Therefore, "Bogus!".


I agree to this except for your wording, and a bit of the science!

Yes, exposure to 730nm does shut the plant down (Phytochrome response to the 730nm or F(ar)R(ed) results in the change from the active chromoprotein [Pfr] to the inactive chromophore [Pr]) and allow for longer (un-needed and rather un-effective) lights on times..This allows for no extra stress or chance of "bisexual expression"..

This _*is*_ documented in several college studies...It is outlined all over the net!...I'll have to poke around for them if you want them but, I got them somewhere.
The amount of any "increase" is not worth the cost in almost every attempt to make that idea work. Best I ever got was about 17% (new strain , not dialed in) and the average was less then 10.

I strongly suspect that the results obtained were due to quality dial in's on the strains.....I mean (and you know this), once you have the strain running at about potential. Your not going to pull out of the plant what it can't do!

Right?

Not attempting to argue my friend - just pointing some extra shit out....


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## Dr. Who (Dec 8, 2016)

RetiredGuerilla said:


> I simulated Alaska's photoperiod in a experiment with a indica. The last 2 weeks the lights were on only 4 hours per day. I kept the lights close and ended up with some unreal smoke with huge trikes. Some white widow fans run them with no light or water the last week forcing the plant to produce more trichomes as a defense mechanism.


The extended lack of lighting at the end of bloom _will not increase trichome size or production!_
This is a myth that has been repeated and repeatedly shot down here, over and over.
I would have ignored this but, I can not let myth grow and flourish !!


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## RetiredGuerilla (Dec 8, 2016)

I'm sorry but those were the results. Like it or not. You think I just made up some tall tale? Short light cycles work awesome as long as temps and light intensity are optimal. Trichomes are part of the plants defense to protect it from insects, critters and such in order for it to reproduce. I'm just trying to impart wisdom from past experiences not disinformation. Rolls eyes


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## Odin* (Dec 8, 2016)

@Dr. Who And I'm not disagreeing with what you're saying (for the most part). However, that (Pfr to Pr) doesn't tell the whole story. There are various other metabolic processes that occur during lights out that a short burst of far red light cannot reproduce. It does not "shorten" your lights out period. Again, if that were true, then 8 hours (or less) of darkness would be ample to maintain bloom (w/far red exposure) as there are a number of documented "10 hours of dark" grows w/o far red. That, and greenhouse growers wouldn't have to utilize "covers" to initiate bloom due to the far red light that plants are exposed to. It would also indicate that those same plants would be able to bloom at any point of the year (at least, here in CA), as there isn't any period of darkness of fewer than 8 hours.

Far red doesn't put them "to sleep" either, the plants own internal clock does. I'm sure that you have noticed that they are "ready for sleep" moments before lights out (regardless of your schedule) and prepared for lights on moments prior. Lights are at full intensity up until the moment that they shut off, but the plants are "asleep" before this happens. Don't need a lab coat and peer reviewed work to recognize that. This, indipendent of far red exposure (if any).

Not arguing, just pointing out that "It isn't as simple as THAT".


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## Dr. Who (Dec 8, 2016)

RetiredGuerilla said:


> I'm sorry but those were the results. Like it or not. You think I just made up some tall tale? Short light cycles work awesome as long as temps and light intensity are optimal. Trichomes are part of the plants defense to protect it from insects, critters and such in order for it to reproduce. I'm just trying to impart wisdom from past experiences not disinformation. Rolls eyes


And just how did we measure the increase? By eye?
I'm sorry man.....but that one is perceived and not actual.....This theory has been disproven time and time again!

Ask this [email protected]

If it did work, don't you think the writers of grow guides would have a page on the idea? Green, Rosenthal, Cervantes (Golly That RM3 guy writes grow guide books too!)
It would be common knowledge and it would be practiced by everyone! 
Does REV or Danko promote the idea in their respective magazine bylines?

Increase trich's? Try a Mag sulfate or a P sulfate supplement with a carb in it.....That actually works!

There are more then a few out there. They have the same formula's and are costly to buy! I can make my own and save a shit ton of my cash over buying name brand one's!

Want the formula's? Ask and I'll give you them!


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## RetiredGuerilla (Dec 8, 2016)

18 hour light cycle decreased to 4 over a 8 week period. Vertical and horizontal lighting. Optimal temps organic soil. Very few growers experiment with photoperiods and the cannabis plants relationship with light. Matsu valley Alaskan thunder fuck ever heard of it? Or the enormous veggies grown there ? Look it up ! Just when you think you know it all some old fart with 30 years of indoor n outdoor experience comes along .... I have read Cervantes book George lassens book and Robert Clark's marijuana botany I love them all. 12/12 is rule of thumb for noobs not the holy gospel the world is flat or you will be burned at the stake. Good god !! Lmao


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## Dr. Who (Dec 8, 2016)

Odin* said:


> @Dr. Who And I'm not disagreeing with what you're saying (for the most part). However, that (Pfr to Pr) doesn't tell the whole story. There are various other metabolic processes that occur during lights out that a short burst of far red light cannot reproduce. It does not "shorten" your lights out period. Again, if that were true, then 8 hours (or less) of darkness would be ample to maintain bloom (w/far red exposure) as there are a number of documented "10 hours of dark" grows w/o far red. That, and greenhouse growers wouldn't have to utilize "covers" to initiate bloom due to the far red light that plants are exposed to. It would also indicate that those same plants would be able to bloom at any point of the year (at least, here in CA), as there isn't any period of darkness of fewer than 8 hours.
> 
> Far red doesn't put them "to sleep" either, the plants own internal clock does. I'm sure that you have noticed that they are "ready for sleep" moments before lights out (regardless of your schedule) and prepared for lights on moments prior. Lights are at full intensity up until the moment that they shut off, but the plants are "asleep" before this happens. Don't need a lab coat and peer reviewed work to recognize that. This, indipendent of far red exposure (if any).
> 
> Not arguing, just pointing out that "It isn't as simple as THAT".


I put it in simple terms for the mass's here...
Ah, your very correct on what gores on at "night" and not so correct on the FR part. I think you may need some further research into the transitional lighting affects of the fr nm bands on plants. 
We agree to disagree on that then.....I'll stick with my college grad studies and personal experiments from them.

Also, I am _not_ saying that FR regulates flowering alone! (although, pigment driven light receptors, effecting plant functions and responses is a rather fascinating study!)

Read some of this as they touch on the subject and the site actually used to list papers on it.....asshats removed them and reduced the price from when I got the damn things from around $300+

The claims are still overblown and I still say it's NOT worth it!

http://growlightsource.com/products/the-flower-initiator-and-booster-grow-lights/
http://growlightsource.com/the-flower-initiator-10-watt-ip65-far-red-indoor-outdoor-grow-light/

Peep this too.

http://www.cannabisculture.com/content/2011/04/18/ask-ed-questions-and-answers-light-deprivation-how-ditch-tarp

Just throwing back my 2cents of proof....

 I'll stick with "We agree to disagree" at any rate.


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## Dr. Who (Dec 8, 2016)

RetiredGuerilla said:


> 18 hour light cycle decreased to 4 over a 8 week period. Vertical and horizontal lighting. Optimal temps organic soil. Very few growers experiment with photoperiods and the cannabis plants relationship with light. Matsu valley Alaskan thunder fuck ever heard of it? Or the enormous veggies grown there ? Look it up ! Just when you think you know it all some old fart with 30 years of indoor n outdoor experience comes along .... I have read Cervantes book George lassens book and Robert Clark's marijuana botany I love them all. 12/12 is rule of thumb for noobs not the holy gospel the world is flat or you will be burned at the stake. Good god !! Lmao


I *like* this! Personally, I hate 12/12 to,,,oh,,pedestrian...


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## Odin* (Dec 8, 2016)

@Dr. Who We both hold degrees (and from what I gather, both in the "sciences"), and I have read plenty regarding far red. Maybe I missed an article, but I have never read one that asserted a short burst (or even up to 30 minutes) was the equivalent of 2 hours of absolute dark, nor have I read one that asserts that photoperiod during flowering can be extended by exposing the plant to a short period of far red prior to "lights out". I'm very sure the latter doesn't exist as far red doesn't really have anything to do with a plants light saturation point or extending it's ability to utilize "more/extended light" in bloom. It does have some effect on "lights out"/initiating bloom. What some articles do suggest/imply is that far red exposure can help initiate/maintain bloom at the cusp of a plants veg-bloom darkness threshold. For example, theoretical cannabis strain "Dank" requires a bare minimum of 11 hours of darkness to initiate/maintain bloom and any less than 11dark will result in veg/reveg/herm. Our grower wishes to run a 13/11 on/off cycle throughout bloom. This puts our plant in a precarious position, it's literally teetering between reveg/bloom and could switch on our grower at any time. In this example, a brief period of far red exposure "may" help maintain bloom and prevent reveg/herming. This is the equivalent to minutes of "extended" dark, not hours of extended light.


En garde!  We can have fun with this.


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## rkymtnman (Dec 8, 2016)

Dr. Who said:


> Increase trich's? Try a Mag sulfate or a P sulfate supplement with a carb in it.....That actually works!


ok, i'll ask. what formulas you got that work for increasing trichs? when? how much? etc.

i've used uvb supplementation for a few years now and like the results but if i could get more trichs i'd be even happier. had to play around with the htg supply uv bulbs cause they will melt your plants if too close.


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## Dr. Who (Dec 8, 2016)

Odin* said:


> @Dr. Who We both hold degrees (and from what I gather, both in the "sciences"), and I have read plenty regarding far red. Maybe I missed an article, but I have never read one that asserted a short burst (or even up to 30 minutes) was the equivalent of 2 hours of absolute dark, nor have I read one that asserts that photoperiod during flowering can be extended by exposing the plant to a short period of far red prior to "lights out". I'm very sure the latter doesn't exist as far red doesn't really have anything to do with a plants light saturation point or extending it's ability to utilize "more/extended light" in bloom. It does have some effect on "lights out"/initiating bloom. What some articles do suggest/imply is that far red exposure can help initiate/maintain bloom at the cusp of a plants veg-bloom darkness threshold. For example, theoretical cannabis strain "Dank" requires a bare minimum of 11 hours of darkness to initiate/maintain bloom and any less than 11dark will result in veg/reveg/herm. Our grower wishes to run a 13/11 on/off cycle throughout bloom. This puts our plant in a precarious position, it's literally teetering between reveg/bloom and could switch on our grower at any time. In this example, a brief period of far red exposure "may" help maintain bloom and prevent reveg/herming. This is the equivalent to minutes of "extended" dark, not hours of extended light.
> 
> 
> En garde!  We can have fun with this.


Precarious - agreed!

It seems that that 2 hr period is shortened to the 5 - 10 min of exposure.....It did work but, didn't really increase yield to any worthwhile result in my test's.....Of course the sellers of those LEDs beg to differ.....I had it out with them by phone on that one....So, I guess in reality. I rather agree with you...other then some minor tech talk....

From a beer commercial - "_I love you man". _Wish we could sit down and have a beer-n-blunt someday!


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## Dr. Who (Dec 8, 2016)

rkymtnman said:


> ok, i'll ask. what formulas you got that work for increasing trichs? when? how much? etc.
> 
> i've used uvb supplementation for a few years now and like the results but if i could get more trichs i'd be even happier. had to play around with the htg supply uv bulbs cause they will melt your plants if too close.



Copy of Botanicare's Sweet Raw:

8 TBL of organic Epsom
1 1/2 tsp Dark Brown sugar.

Boil in 4 cups of RO till well dissolved.

Pour that into an opaque gallon jug and add RO to fill.

Usage chart:

week before the flip
5ml per gal added to feed
Week 2
10ml per
Week 4 
15ml per
week 6
20ml per

Every feeding.

Potassium Sulfate formula (Resinator/Terpinator but mine is a better ratio and feed charting)

https://www.rollitup.org/t/the-correct-homemade-terpinator-resinator-formula.915401/


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## Odin* (Dec 8, 2016)

@Dr. Who One of these days. I'll introduce you to some of my favorite brews and some of my favorite "flavors".


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## Ghammondeggs (Dec 12, 2016)

It was my understanding that the flash of deep red lighting, say, 15 to 20 minutes before lights out was to mimic the spectrum produced when the sun passes through the horizon during sunset. This was to make the plant "go to sleep" and start using the sugars produced throughout the day much quicker than they would usually (which is 2hours). You can find an interesting Harley Smith grow class on youtube. Very interesting fellow! Sorry if this was already Discussed, but this topic has always interested me!


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## Rob Roy (Dec 12, 2016)

There have been some interesting points brought up in this discussion. I'm no scientist, but I think people who experiment with flowering times might want to consider the genetic heritage of the strain(s) they are working with. 

Many popular strains today are hybrids, but if someone were working with a pure or mostly Indica or a pure or mostly Sativa, I think the plant responses to any flowering light schedule changes might vary.


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## hyposomniac (Dec 12, 2016)

rkymtnman said:


> ok, i'll ask. what formulas you got that work for increasing trichs? when? how much? etc.
> 
> i've used uvb supplementation for a few years now and like the results but if i could get more trichs i'd be even happier. had to play around with the htg supply uv bulbs cause they will melt your plants if too close.


Would you share your uv recipe?


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## Lucid1991 (Aug 10, 2022)

So with auto flowers in my case I have a lot of seeds and it just so happens I got an auto flower now reading up on far red light and how they use the far red light to tell when it's the end of the day can you trick autoflowers into having a longer day than 24 hours by using far red light say at 36 hours and then triggering the end of the day response to make autoflowers grow more. more or less the autoflower uses the infrared to end
it's day whenever it is that you tell it the day is over


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## Lucid1991 (Aug 10, 2022)

And then also in that same regard I read that green light does not mess up the light cycle if used during the plants sleep stage and that 25% can be green light so what if you use green light in the night cycle


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## Lucid1991 (Aug 10, 2022)

Furthermore using headlight cycle who says that their days have to be 24 hours what if someone where to do a 48 hour on 12 hour off continually would that make the plant think that the 48 hours is one day possibly using infrared at the end of 48 hours and then at the end of the 12 hours I've always been extremely interested in the growth of these plants and I've grown 3 years now and this will be the first year that I will be able to see my plants too flower due to stupid decisions I made previously which took me away from them but I've been good lately. So thank you for any and all feedback


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## Lucid1991 (Aug 10, 2022)

Lucid1991 said:


> Furthermore using headlight cycle who says that their days have to be 24 hours what if someone where to do a 48 hour on 12 hour off continually would that make the plant think that the 48 hours is one day possibly using infrared at the end of 48 hours and then at the end of the 12 hours I've always been extremely interested in the growth of these plants and I've grown 3 years now and this will be the first year that I will be able to see my plants too flower due to stupid decisions I made previously which took me away from them but I've been good lately. So thank you for any and all feedback


Far 
Red light cycle


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## mudballs (Aug 10, 2022)

Lucid1991 said:


> can you trick autoflowers into having a longer day than 24 hours by using far red light say at 36 hours and then triggering the end of the day response to make autoflowers grow more. more or less the autoflower uses the infrared to end
> it's day whenever it is that you tell it the day is over


I dont think we understand ruderalis inflorescense/florogenesis phytohormones well enough to say yes or no. Good grief that's "dr.frankenstein your 6:30 appointment is here" stuff


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## simpleleaf (Aug 12, 2022)

BobCajun said:


> Here's something I found interesting, from this article. It appears that weed can flower under surprisingly long days. The flowering phases were identical with 12/12 and the natural outdoor day lengths which varied from more than 14 to less than 12. This may explain why people have flowered with 14 hour days while using end of day far red treatments. I couldn't find any evidence that such treatments are capable of reducing the number of dark hours required for short day plants to flower, though it was useful for increasing stem length.
> 
> It's probably possible to flower with 14 hour days even without any far red treatments and the length of time to maturity may not be that much different from 12/12. Can't really tell from this table because at the end the days are less than 12 hours anyway, but I think it's possible. At least they started flowering and kept flowering at the same rate as 12 hours in the early phases, which is unexpected. Since the table shows that florets formed with 14.16 hours, they must have started being induced a week earlier with 14.4 hours. That particular strain, G5, was a high CBD strain, but it may be similar for THC ones.


The two plants I'm currently blooming are months (not yet a year) behind schedule because I ran them under lights with very few blue diodes (maybe 15%). It was a combination of light fixtures I hadn't tried prior. After 4 months on 6-hours darkness they bloomed. I wasn't expecting them to bloom on 18-hours light per day ...


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