Running hps 13/11 to increase yield

CannaBruh

CannaBruh

Well-Known Member
Fevs said:
@BobCajun Thanks for your in depth reply. This really interests me. My electric is 1/3 of the day price when I use leccy between 00:00 and 07:00. So 7 hours at bargain rate... just having to pay for another 5 hours or so will be very cheap compared to the usual 24-0 auto's.
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Which when weighted against any potential "loss of yield" might actually outpace any losses, would need lots of metrics but you're onto stuff that I like to ponder.
 
T

THE KONASSURE

Well-Known Member
BobCajun said:
Yeah actually using low hours is said to cause herms. That's why it may be best to use 12/12 until the last week. They wouldn't be able to crank out ripe pollen sacks in just a week I don't think. That's why my plan is 13/11 for 6 w then 12/12 for 2 and a lesser amount on the last week, somewhere around 8-10. Just a matter of seeing how low you need to go to get them to ripen in that last week. In Kabul the days only get down to 9.9 hours so 10/14 would probably suffice.

Somebody mentioned that they may be getting higher yields from fewer hours. It's a possibility because I've read an article on other short day plants and they found that long hours of light actually inhibited flowering somewhat, using the same hours of darkness. Some plants flower more on 8 hours than 12 apparently. However, they didn't experiment to see if they needed that few hours for the whole flowering period or maybe just the end of it. The article is called "Floral Inhibition in Relation to Photoperiodism in Biloxi Soybean, G. S. Sirohi & K. C. Hamner".

I have also read an article on Cannabis specifically which showed that 11 hours gave a lower yield of weight and potency than 12. The article is called "OPTIMISATION OF CANNABIS SATIVA L AS A PHYTOPHARMACEUTICAL, A thesis submitted by David Potter JP". You can find the pdf if you google it. That's also the article that said that all strains flowered with 13/11 as soon as with 12/12, just that the 13 hour ones didn't ripen as fast though almost all produced higher yields. So I don't think using low hours for the whole flowering would be wise but for the last little while it may be fine and may even cause more trichs to form.

Another thing I'm doing btw is giving them 24-48 hours straight light on their last day. That makes up for the lower hours on the last week and packs on some final weight and potency. I did that last time and it turned out fine. I only turned the lights down to 9/15 for the last 3 days though and could barely see any extra ripening. I think it needs to be a whole week. I also stopped giving them 36 hours dark before chop. That just burns off all the starch and makes less weight. I'm curing it now anyway so the starch gets converted to sugar, which gives a sweet taste. The darkness before chop does increase quality some but at the price of weight reduction. My last batch turned out fine with 24 hrs light followed by immediate chopping and curing, meaning quick curing with heat like flue curing tobacco. 3-4 days later it's cured and dried. Wasn't harsh like the uncured was even with the 36 hrs dark at the end.
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I had some random beans I put into bloom 2 weeks ago and today 2 of them were males and ready to drop in a day or 2, so I`d say 2 weeks is as fast as regs can do it, auto`s maybe a week
 
BobCajun

BobCajun

Well-Known Member
THE KONASSURE said:
I had some random beans I put into bloom 2 weeks ago and today 2 of them were males and ready to drop in a day or 2, so I`d say 2 weeks is as fast as regs can do it, auto`s maybe a week
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Good to know, the last week should be safe on low hours then, two may be pushing it. I actually recall trying 13 hours once before and although I switched back to 12 a few weeks before chop I did get my biggest yield from that batch. Didn't seem to have any negative effect. They were budding up as usual. The plants got pretty big though. I just went back to straight 12/12 after that but my yields have been lower since. That may have been what made the difference. I did have one NLxBB plant in there that time though. Didn't grow it again because it was stretchy and flavorless. Anyway, I got significantly more weight that time than any other as I look back on it, for whatever reason. It's more likely that it will be beneficial than negative, from my experience.
 
T

THE KONASSURE

Well-Known Member
BobCajun said:
Good to know, the last week should be safe on low hours then, two may be pushing it. I actually recall trying 13 hours once before and although I switched back to 12 a few weeks before chop I did get my biggest yield from that batch. Didn't seem to have any negative effect. They were budding up as usual. The plants got pretty big though. I just went back to straight 12/12 after that but my yields have been lower since. That may have been what made the difference. I did have one NLxBB plant in there that time though. Didn't grow it again because it was stretchy and flavorless. Anyway, I got significantly more weight that time than any other as I look back on it, for whatever reason. It's more likely that it will be beneficial than negative, from my experience.
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seen that before with big bud crosses no smell but huge yields, I wonder if 2 weeks of 16/8 around week 4/6 of flowering then drop to 10/14, if that`d yield more and get more smell

you see more colour changes with shorter days and more smell, I always notice the plants smell more on lights off, but that could be due to temps and RH as well as biochemistry
 
Michiganmeds1982

Michiganmeds1982

Well-Known Member
I have done up to 13.5/10.5 and thought it worked pretty good. I'm sure some strains may not respond as well but I never found it.

Seemed to harvest pretty good and Mabey a few days faster
 
BobCajun

BobCajun

Well-Known Member
THE KONASSURE said:
seen that before with big bud crosses no smell but huge yields, I wonder if 2 weeks of 16/8 around week 4/6 of flowering then drop to 10/14, if that`d yield more and get more smell

you see more colour changes with shorter days and more smell, I always notice the plants smell more on lights off, but that could be due to temps and RH as well as biochemistry
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You can't use any longer than probably 13.5, as the previous post mentioned, during flowering because they'll start reveging within about a week. I did it before to see what would happen. The buds started getting very loose and leafy. The only time you could use long days is at the very end of flowering, like maybe 3 days at most.

I'm giving mine 24 hours or so of steady light on their last day. I read that 48 hours of steady light right before harvest produced significant boosts in secondary plant products. It wasn't about Cannabis though, some other plants. It worked in all the species they tried it on though. They said that more than 48 didn't increase the boost, so 48 is the most that's probably worth doing. 24 also gave significant boosts. I haven't tried 48 yet. They got about 30% more carotenoids. Whether you would get similar increases in cannabinoids I don't know. Probably takes longer than that to produce them. There's likely some slight benefit though.

You may have heard of 48 hours of dark right before harvest, but this is sort of the reverse. With 48 hours of dark you would LOSE, at least on weight, and I haven't seen reliable evidence that it helps, other than by burning up all the stored starch and thereby maybe making it less harsh.
 
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torontoke

torontoke

Well-Known Member
I've run all sorts of light schedules myself and experimented with a few not even mentioned in this thread.

I use 12:1 or glr for vegging and I now use 8/16 to flower. I'd say that using 8/16 I yield on average 75-80% what I used to yield with 12/12.
I use 8/16 because the loss of yield is worth the energy savings and heat problems. Plants also finish at least a week earlier with as much potency imo.


Everyone has their own methods that they prefer and I think the best advice is to experiment and tinker with your grow and dial it in to what works best for you.
 
Doomhammer69

Doomhammer69

Well-Known Member
Its my understanding, every time you change the light cycle you cause stress to the plant. Which in turn slows down the flowering process. So I have always subscribed to the theory, I pick a light cycle for veg and keep it , then When I switch to flower i keep it at the time period I picked.


Also I would like to add (a tangent) Its my understanding that Cannabis does not absorb light after 18 hrs? One thing I have noticed with a lot of my grows is at about hr 16 or 15 my plants droop and sleep. So I never run 18 hrs any more just 16 on for veg and 12/12 flower
 
Olive Drab Green

Olive Drab Green

Well-Known Member
Doomhammer69 said:
Its my understanding, every time you change the light cycle you cause stress to the plant. Which in turn slows down the flowering process. So I have always subscribed to the theory, I pick a light cycle for veg and keep it , then When I switch to flower i keep it at the time period I picked.


Also I would like to add (a tangent) Its my understanding that Cannabis does not absorb light after 18 hrs? One thing I have noticed with a lot of my grows is at about hr 16 or 15 my plants droop and sleep. So I never run 18 hrs any more just 16 on for veg and 12/12 flower
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I have never had my plants droop on a 24/0 cycle. What exactly are you doing to your plants? Also, Cannabis falls into that category that doesn't necessarily need a dark period except for flower. Because the flowering hormone builds in the dark period. However, that said, it roots best in the dark.
 
F

Fevs

Well-Known Member
I veg photoperiods on 24-0 and grow autos on 24-0.

Surely vegging on 24-0 then switching to 14on-10off, would be better than doing 18on-6off then 14-10. Maybe 18-6 to 14-0 isn't a big enough drop to flower...

Anybody ever ran 24- or 18-6, then just changed it by like 15 minutes a day? Like outside when the days shorten...? That would be interesting.
 
Doomhammer69

Doomhammer69

Well-Known Member
Olive Drab Green said:
I have never had my plants droop on a 24/0 cycle. What exactly are you doing to your plants? Also, Cannabis falls into that category that doesn't necessarily need a dark period except for flower. Because the flowering hormone builds in the dark period. However, that said, it roots best in the dark.
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To answer your question, this is what Im doing. seems to be working.
 

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Olive Drab Green

Olive Drab Green

Well-Known Member
Doomhammer69 said:
To answer your question, this is what Im doing. seems to be working.
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Your plants probably droop due to lessening of water. They don't sleep. They don't need a dark period. They only droop during the dark period due to the lack of pressure caused by reaction to the absent light. It creates kind of a hydraulic pressure or suction towards the leaves.
 
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Doomhammer69

Doomhammer69

Well-Known Member
Olive Drab Green said:
Your plants probably droop due to lessening of water. They don't sleep. They don't need a dark period. They only droop during the dark period due to the lack of pressure caused by reaction to the absent light. It creates kind of a hydraulic pressure or suction towards the leaves.
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Then why in the morning even though there was no water given to them, their up and happy?
 
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Olive Drab Green

Olive Drab Green

Well-Known Member
Doomhammer69 said:
Then why in the morning even though there was no water given to them, there up and happy?
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Because you're full of shit or you misconstrued something you saw. That's just a guess, but I'd guess a pretty good one. Not even trying to talk shit, but you don't have correct information. They don't sleep, especially in the light under any circumstance I can think of. Even in the dark, they're still growing.
 
Doomhammer69

Doomhammer69

Well-Known Member
Olive Drab Green said:
Because you're full of shit or you misconstrued something you saw. That's just a guess, but I'd guess a pretty good one. Not even trying to talk shit, but you don't have correct information. They don't sleep, especially in the light under any circumstance I can think of. Even in the dark, they're still growing.
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Ah we found one guys.. the elusive internet tough guy lolbongsmilie Ignored..bye bye
 
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