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Manipulating Photo Period

I Care

Well-known member
I really cant tell you exactly where I get all of my info from, but I read about one person using a 6/2 for automatic nuggets. Their explanation is that there is evidence(which I cannot present to you). Their suggested evidence was stating that after 6 hours, a plant may reduce or seize photosynthesis. Only other thing I could find on the topic suggested that plants actually begin protecting themselves after 6 hours of light.

What I want to know. Does this mean that a plant only needs 6 hours of light? I’m talking about a regular female, not autoflowering, cannabis plant.

does this mean that a plant will photosynthesize 6 hours and the rest of the day the plant makes resins?

I know that this is probably the wrong EDIT (right) place to seek answers to such questions, but my serious interest is the idea of having a modern controller and setting up a cycle of 6/12. That would provide you with 63 nights in 48 days. So with a photoperiod strain would you get the same quality bud but lower yield in 48 days, that’s about half the energy cost for your lighting? Would you the same yield in 63 days with 25 percent reduction in energy cost?

I am aware that people have done the pull back a half hour a week and stop at 9 hours to finish and they don’t EDIT (some do) like the result. Maybe EDIT (those that don’t prefer the results) their results have had more to do with night extension rather than the reduction in day time.

I am also aware of claims that someone back in the 2000s was like 24 hours on 12 hours and actually having increase yields in the same number of weeks as they would use 12/12. I would not try this because it would actually cost more more for the experiment.

I find it strange not to find anyone’s study on this procedure on the web. 75% of lighting for 75% of the days would be exactly 56.25%. So that would be a 43.75% minimum cost benefit and light saving. Then that gives you 7 rounds a year plus 4 days for turn around between each round.

Is there anybody here who knows of any existing evidence for 6/12 6 on 12 off lighting for photoperiod plants?


I know there’s a lot of breeders here, it would make way too much sense for breeders if this worked. It would speed up your breeding times by 25%.

Edit: P.S.; somebody gotta know somebody that did this thing. If not, do I gotta be somebody who somebody knows who did this thing.
 
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I Care

Well-known member
I just read an entire evening on this.

Happy to have been the guinea pig while trying to help the community.
Hopefully at least one person besides myself was entertained.

Felt like this journal needed a better write up to end it.
Reduced light cycle flowering isnt for everyone and anyone focused on the negatives or potential loses we’re not the intended audience. In fact it was a grow journal for myself that I thought others might be interested in following along with.
There’s been much back n forth and thankfully at least one positive comment for every negative post or pm I received.

I appreciate every single person that chimed in on this journal and thank you all for taking the time.

I have since stopped using the glr to veg but still use only 8/16 to flower. Started a new journal awhile back
https://www.rollitup.org/t/shootin-fer-mids-if-im-lucky.957103/

I would rather not get into light cycle talk in my new journal and wish the best of luck to everyone in their gardens going forward.

Hopefully you all harvest twice as much as you were expecting

Tt

They claimed awful yields. It seems that he never tried a shortened day because of his controls. He doesn’t want just anybody looking at his threads so I don’t know where he is at after 5 years.


@Dime you gave 6/12@18hr a couple runs? guess it would be a 6/12 Cycle


We have things like this and this now that quickly pay for themselves.
I already have the controller, I thought it was cool to have a guage and timer in one so I spent the extra couple bucks over having a knob.
I’m not advertising this stuff, just needed a quiet ec motor fan and upgraded with the controller. Slacking for 6 months to get a set of gauges when I’m out. Actually really stoked on the purchase so long as nothing cooks. Time will tell.

IMG_0821.jpeg

IMG_0820.jpeg

I can imagine all the benefits of 6/12 cycling, 18 hr days.
If something goes wrong in the morning, it’s only 6 hours damage rather than 12. Can also imagine that maybe the plant thinks it’s winter, decides to knock herself up and pops nanners early into flower. That would be a potential con.

This would be a lengthy experiment, wouldn’t intimately need to be compared to outdoor with my small rec limit. Somehow becoming more efficient with the least efficient way to grow plants.

I know there’s other ways I could be more efficient. All of them would involve spending much more than this added accessory.
 
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I Care

Well-known member
There must be some variety with origins specifically from the shaded side of a high latitude valley that would thrive like this.
 

Creeperpark

Well-known member
Mentor
Veteran
The best photoperiod will be the one closest to the natural growing environments that the strains originated from. If you grow a desert plant in a tropical environment or a tropical plant in a desert environment you will have problems with yield in the end not to mention prone to diseases.
 

Dime

Well-known member
@Dime you gave 6/12@18hr a couple runs? guess it would be a 6/12 Cycle.
No I haven't swayed much from 12/12, I went to 10 for a few long flowering ones and yield and quality suffered.I read about 10 being the minimum duration required for thc production. I also believe drastic light manipulation will confuse and may result in intersex for many varieties. Before chemical feminizing they used drastic cycles to make female seeds.
 

TrainingHay

Member
When I started growing authentic Sativa plants indoors, it was suggested that I shorten the day a couple hours. I had a bay of regular modern indica genetics in the same room. Every single plant benefited for 10 hour vs 12 hour days, not just the landrace. I'd start there before getting all fancy.
 

Ringodoggie

Well-known member
Premium user
@I Care I did this a few years back. I think I documented it here at ICMag. I'll see if I can find the thread. The thread title was something like "changing the Circadian Cycle blah blah something"

The timer schedule was a 14 hour day with 12 hours of dark and 2 hours of light. I also recall using a blue light at night as I recall something about the blue light providing what was needed for photosynthesis but didn't interfere with the flowering cycle. So, in essence the plant got 14 hours for photosynthesis and 12 hours for flowering, all in 14 hours.

It worked fine and I cut a 63 day flowering time down to 40-something days (maybe less). As you might expect, yield suffered.

I'll see what notes I can find.

EDIT: Here is the timer schedule.

Event 1: ON - Sunday: Noon (12 PM)
Event 2: OFF – Sunday: 2 PM

Event 3: ON – Monday: 2 AM
Event 4: OFF – Monday: 4 AM

Event 5: ON – Monday: 4 PM
Event 6: OFF – Monday: 6 PM

Event 7: ON – Tuesday: 6 AM
Event 8: OFF – Tuesday: 8 AM

Event 9: ON – Tuesday: 8 PM
Event 10: OFF – Tuesday: 10 PM

Event 11: ON – Wednesday: 10 AM
Event 12: OFF – Wednesday: Noon (12 PM)

Event 13: ON – Thursday: Midnight (12 AM)
Event 14: OFF – Thursday: 2 AM

Event 15: ON – Thursday: 2 PM
Event 16: OFF – Thursday: 4 PM

Event 17: ON – Friday: 4 AM
Event 18: OFF – Friday: 6 AM

Event 19: ON – Friday: 6 PM
Event 20: OFF – Friday: 8 PM

Event 21: ON – Saturday: 8 AM
Event 22: OFF – Saturday: 10 AM

Event 23: ON – Saturday: 10 PM
Event 24: Off – Sunday: Midnight (12 AM)
 
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I Care

Well-known member
@I Care I did this a few years back. I think I documented it here at ICMag. I'll see if I can find the thread. The thread title was something like "changing the Circadian Cycle blah blah something"

The timer schedule was a 16 hour day with 12 hours of dark and 2 hours of light. I also recall using a blue light at night as I recall something about the blue light providing what was needed for photosynthesis but didn't interfere with the flowering cycle. So, in essence the plant got 16 hours for photosynthesis and 12 hurs for flowering, all in 16 hours.

It worked fine and I cut a 63 day flowering time down to 40-something days (maybe less). As you might expect, yield suffered.

I'll see what notes I can find.

EDIT: Here is the timer schedule.

Event 1: ON - Sunday: Noon (12 PM)
Event 2: OFF – Sunday: 2 PM

Event 3: ON – Monday: 2 AM
Event 4: OFF – Monday: 4 AM

Event 5: ON – Monday: 4 PM
Event 6: OFF – Monday: 6 PM

Event 7: ON – Tuesday: 6 AM
Event 8: OFF – Tuesday: 8 AM

Event 9: ON – Tuesday: 8 PM
Event 10: OFF – Tuesday: 10 PM

Event 11: ON – Wednesday: 10 AM
Event 12: OFF – Wednesday: Noon (12 PM)

Event 13: ON – Thursday: Midnight (12 AM)
Event 14: OFF – Thursday: 2 AM

Event 15: ON – Thursday: 2 PM
Event 16: OFF – Thursday: 4 PM

Event 17: ON – Friday: 4 AM
Event 18: OFF – Friday: 6 AM

Event 19: ON – Friday: 6 PM
Event 20: OFF – Friday: 8 PM

Event 21: ON – Saturday: 8 AM
Event 22: OFF – Saturday: 10 AM

Event 23: ON – Saturday: 10 PM
Event 24: Off – Sunday: Midnight (12 AM).
You got 12 days out of a week with 2/12.
:D Pretty impressive.

@Dime you gave 6/12@18hr a couple runs? guess it would be a 6/12 Cycle.
No I haven't swayed much from 12/12, I went to 10 for a few long flowering ones and yield and quality suffered.I read about 10 being the minimum duration required for thc production. I also believe drastic light manipulation will confuse and may result in intersex for many varieties. Before chemical feminizing they used drastic cycles to make female seeds.
Good shared word response. I was considering THC took longer than the bare minimum before the leaves get enough sun for the day. Didn’t know the word is intersex. I was warned that interrupting dark period can cause it, resulting in a shift to feminized seed production.


The best photoperiod will be the one closest to the natural growing environments that the strains originated from. If you grow a desert plant in a tropical environment or a tropical plant in a desert environment you will have problems with yield in the end not to mention prone to diseases.
If you produced seeds with the absolute best results of ringodogs method 2f/12blue, from seed. Then would you end up with a quality plant that is way cheaper to produce? I think the tech and market is here now for someone to get into it. Might be the next big thing since autoflower. See work has been done for fast flower strains from what I have seen while pondering around the web for seeds.


will have less time to think about unusual things when I get back to work next week. I need to start carrying a joint me at all times. For the next time one of my supervisors has some issue with be coming in to work that day, can smoke one instead of two smokers trying to sort out problems without smokin.
 

Ringodoggie

Well-known member
Premium user
I had to go back into my first post and edit the numbers. 12 plus 2 equals 14, not 16. LMAO Oops.

So, the 63 day cycle was shortened to 37 days. As mentioned yield suffered greatly.
 

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