How Do I Manipulate The Photoperiod For Larger Yields?
- Thread starter Bush Doctor 77
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Interesting indeed
Remystemple
Well-Known Member
I think i'll wait to see a few journals. 40% for 40% seems like, why bother when you can just get the same yield per light energy with 12/12. if it was a 40% yield increase with say 20% more energy use would be worth it. unless i'm reading it wrong 
Article lost me at:
Not sure what they even mean by that as the sun comes up 7 times here a week
. Cannabis is a short day long night flowering plant (well regular seeds anyway), so not sure I see how you could benefit by making daylight time longer. Guess I am of the mindset that the plants do a lot of their growing time in the dark, as like a battery on your phone once it is charged up it can't store anymore energy until it uses some of it.
Not sure what they even mean by that as the sun comes up 7 times here a week
. Cannabis is a short day long night flowering plant (well regular seeds anyway), so not sure I see how you could benefit by making daylight time longer. Guess I am of the mindset that the plants do a lot of their growing time in the dark, as like a battery on your phone once it is charged up it can't store anymore energy until it uses some of it.
Not sure what they even mean by that as the sun comes up 7 times here a week
The article is just saying, in a weird-ish way, that the manipulated light schedule gives the plant 5 light cycles (days) even though 7 calendar days (and real sunrise/set cycles) occur outside of the grow space.
It's trying to say that with the longer day period that the plant will build up more energy to use during the night cycle. As the night cycle remains 12 hours, the plant remains in flower.
Think of it kind of like this: Take a balloon and fill it with 1 cubic foot of air (representing a normal 12hr daylight period), and then let the air out (representing a normal 12hr night cycle.)
Now instead of 1cuft of air, fill that balloon with 1.6cuft of air and let it out. The larger air volume inside the balloon creates a greater pressure/energy release as the air is allowed to escape. So the article is saying that giving a little more light during the day cycle gives it more energy to burn during the night cycle for growth.
Remystemple
Well-Known Member
another thing to keep in mind is the cost of power at peak hours. i set my lights to come on at 6pm, as the rates are lower between 6pm and 6am. i wouldn't want to run my flower lights during peak hours, at least not that much. it would add a lot to the cost of hydro
Back to my battery comparison though if it is charged fully it can't be charged more, or if the balloon can only hold 1 cu ft you can't put more than that in it
.......It would be hard to experiment as the usual tons of variables and would vary a lot by strain potentially, but would be an interesting experiment for sure. Article kinda throws out a "theory" w/o backing it up with much (and an older article at that ), but like Remystemple pointed out if it costs you 50% more in your power bill for a 40% gain kinda going backwards and not gaining much . It's like the folks that go with the "gas lighting" theories feel that since it's a short day long night flowering plant it can only store so many hours of energy and running your lights longer than that only makes the power company happy as the plant just shuts down it's intake (like when a battery is charged it either quits taking more or it blows up ). When I first started I was running my boxes in Veg at 24/0, went to an 18/6 as I bought into "the plant needs to rest" theory and now I'm at around 14/10 for Veg, and haven't really noticed any discernible difference one way or the other (but I rarely grow the same strain back to back anymore, and my cloning luck has become horrible as of late (haven't figured that out yet but thinking my cloning gel contaminated or just old), so some things can be strain specific or even pheno specific as two beans of same strain rarely act totally the same it seems (minor differences mostly, so most of my beans seem to be stable strains).
Anybody decides to experiment keep us all in the loop, as it is always interesting to experiment if nothing else, and sometimes folks do reinvent the wheel so to speak thinking outside the box.
Oh absolutely. I wasn't trying to support it, just maybe explain the concept a little better.
Back to my battery comparison though if it is charged fully it can't be charged more, or if the balloon can only hold 1 cu ft you can't put more than that in it
Agreed. It would be a bit of a pain to set it all up, but the results would certainly be interesting regardless of outcome.
Article kinda throws out a "theory" w/o backing it up with much (and an older article at that
I noticed that as well. Not much to really substantiate the claim, and expecting to take it at face value. Not saying the concept isn't interesting, at least a bit, however it would have had a bigger impact with some data points backing the information put forth.
I'm a 16/8 guy myself. I get why others go for 24/0, 20/4, 18/6, etc. My understanding of plant science, while far from a professional level, and mainly acquired through decades of gardening, is that as you suggest with the battery analogy. A plant can intake X amount of light per daylight cycle. Weaker lighting means you need more of it to reach that point and this is achieved through longer daylight periods. This seems to be why some choose to supplement CO2 combined with higher intensity lighting. The additional CO2 allows for more light intake and processing, thus increasing vegetative growth.
While I haven't really dug into it a lot, my best guess tells me (setting CO2 supplementation aside) that somewhere there lies a balance point between the day/night cycle, growth rate, and the overall cost for that time period. Something where a longer day cuts enough time off veg to make the overall cost of running lighting longer ends up actually costing less. Where/if that point exists is something I cannot personally attest to. It does make sense that it would exist though. Take a 30-day veg for example, to make the math a little easier. If you run at say, 20/4, that is 600 hours of light in the period. At 18/6 it's 540 hours, and 16/8 it's 480. For the sake of discussion let's assume that the 480 hours of vegetative light would produce the results necessary to flip to the flowering stage. If that is true, than a 20/4 light cycle would be to that point (in theory) a whole 6 days earlier. In turn, there would be a savings of 6 days and 120 hours of running the lighting.
Now real world application isn't quite that cut and dry. It is an interesting concept though, and something I need to look into a bit more. Exactly how many total hours of lighting does a plant take to hit the sweet spot in veg to initiate flowering. The data of a power company charging less from 6p to 6a is one example. That's 12 hours of cheaper rates. Some companies go on usage tiers (mine does), and other have their own methods for calculation. This is where the balance portion of cost comes into play, IMO. On a 12hr cheaper rate tier, something like 16/8 may take a little longer to reach the same number of hours, but the overall cost can be less as only 4 hours (or 6 if 18/6 cycle) would fall outside of those cheaper times. Running 20/4 would see 8 hours of peak rate, and even though the overall time is less, the cost would be more. On a usage tier system, not so much since it's by total usage and 500 hours of light is 500 hours of light regardless of how long per day.
Definitely. The biggest breakthroughs come from a different approach. Whether that's from a goof up, or just someone not boxed into the general way of thinking, there have been so many new ideas and improvements in all aspects of life and not just gardening. If someone has a need and can't screw around, there is plenty of good information out there to get them from start to finish on a grow and be somewhat successful. OTOH, when someone has the time and resources to tinker, that is when things can get really interesting. So many things we take for granted now were once a convoluted idea that someone was laughed at for sharing. LST, SCROG, SOG, mainlining, quadlining, backbuilding, hydro, and the list goes on and on. At some point those were all brand new ideas, and needed to be proven to work. Now here we are.
Through experimentation, reproducing results, and sharing knowledge these ideas and many, many others are now mainstream in their acceptance. There are so many ways to do a grow now, and be successful, that the options seem almost limitless. Great time to be alive, IMO. From where we once were with needing high consumption lighting, abundant space, and still not being guaranteed results; now we can pick from an almost overwhelming array of options to tailor a grow to fit our personal needs. Whether that is a micro grow, a space bucket, various sizes of tents, to who knows what. Soil? Coco? Hydro? LED, CFL, HID? Tent? Closet? Room? Entire house??? The times they are a changin.
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- #9
Bush Doctor 77
Well-Known Member
Hopefully one of the State Universities where it is legal will undertake to gather some date on photoperiod manipulation. It will require $$$$ to collect all the data needed. Ideally, it would include in depth chemical analysis.
That certainly sounds like a better use of funding than finding out the effects butterfly urine. 
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- #11
Bush Doctor 77
Well-Known Member
Unless butterfly urine can cure cancer, prevent malaria...That certainly sounds like a better use of funding than finding out the effects butterfly urine.
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