3 on/9off utilizing DIY 730nm PFR pontoon and a tentacle of light

and so it begins...
this cab:
View attachment 2949878
this light:
View attachment 2949879
this rpi controller:
View attachment 2949880

on a 3on, 9off light schedule, triggering PFR response with this:
View attachment 2949882

using a coffee container, my own DIY version of this (using 1/4" porous soaker hose and fittings):
View attachment 2949883

in a mix of coco/peat/perlite, using OC+ CRF ferts in a 'soilponics' type setup (flooded medium, constant air).

inside is crowded:
View attachment 2949884

that's an old, woody CBD Critical that once was a party cup mom.

primary purpose is to see if it'll flower, and if so, can I cut flower time in 1/2

My guess is it won't flower with only 9hrs of dark. Majority of strains start at 10-11hrs dark period.

Medinugs said:

My guess is it won't flower with only 9hrs of dark. Majority of strains start at 10-11hrs dark period.

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but that's the point of the PFR pontoon - gives me 2 hours of dark back.

Cant see your pics. Maybe i'd better understand your concept if I could see pics. You lost me though with the 3 on 9 off, is it to supplement another light source on 12/12 photoperiod?

having issues editing the post - will get it fixed eventually.

here's the science behind using 730nm to simulate sunset:
http://indagrow.com/pdf/420-Pfr-PontoonIntro.pdf

so, I'm literally attempting run a 12 hour "day" cycle, with 3 hours of light, and 9 hours of darkness. The flash of 730nm means the plants hormones flop to dark 2 hours faster than without it, thus allowing me to shorten my night. I'm still counting on this strain to be about to handle 11 hour night and still flower thought.

It depends on strain too. Indicas do not take to well to anything other than 12/12. Sativas like 13/11 or 14/10 with the pontoons. With hybrids. Sativa doms can do 13/11 or 13.5/10.5 but indica doms still work best at 12/12 . Its really just trial and error til you find what your strains like. Until you do, yield can possibly suffer...

hyroot said:

It depends on strain too. Indicas do not take to well to anything other than 12/12. Sativas like 13/11 or 14/10 with the pontoons. With hybrids. Sativa doms can do 13/11 or 13.5/10.5 but indica doms still work best at 12/12 . Its really just trial and error til you find what your strains like. Until you do, yield can suffer...

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I'll defer to your experience here - I just think if it's possible to cut flower in half it would benefit lots of small time personal growers so that's why I'm giving it a shot. I'm fully aware that even if it 'works' it'll affect yield, but if it turns out it doesn't cut yield down by more than 1/2, then it could be worthwhile for the time-save to some.

cab:


controller:


light:

my 730nm pfr light:

using this type of aerator:


sorry for all of the posts - cannot get an edit to work on my original first post.

Interesting experiment you got here. I have read theories about the last few hours of light being a dead time for growth and that you could run 9L/12D, but your proposal is extreme.

Naturally cannabis can flower with less than 14.25hrs of daylight(will take a while to transition fully though)...that means about 10hrs of darkness is the trigger point. As we know, every strain is different, but it's a good starting point to think about. This is where the 14/10 cycle is the truest test for concept. You will have somewhat less than that in real hours, so it will be a good test too.

With short light cycle it will play to your favor in not breaking down the flower hormone fast enough, and they will probably flower.
The thing I am questioning is that with less light, there will be less photosynthesis, and thus yield.

To be able to edit..use the go advanced option

I've found growers claiming to have no problems doing 6 on, 12 off.... so I'm just going a little further

Im not following this. I see white leds so total wrong colors and if i read right you want to do 6 hours of light only? outdoors gets by on minimal 8 hours direct light. if you singl grow like this your gonna get few grams at best so what would be any possible positive to this?

caretak3r said:

I've found growers claiming to have no problems doing 6 on, 12 off.... so I'm just going a little further

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How was the yield. and did they do it for 56 24hr days...or 56 18hr days?

FilthyFletch said:

Im not following this. I see white leds so total wrong colors and if i read right you want to do 6 hours of light only? outdoors gets by on minimal 8 hours direct light. if you singl grow like this your gonna get few grams at best so what would be any possible positive to this?

Click to expand...

This is the second time you have dropped in on something LED with totally wrong and obviously non-expireienced information. You should look at what a white led looks to plants...check out a special graph sometime.

need to dig to find all the links, here's one on RIU:
https://www.rollitup.org/general-marijuana-growing/258737-hbrs-6-12-time-machine.html

and look for posts on icmag by Blckbrd on icmag ("effects of different photoperiods on flowering")
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okay, from here on out I will refer to photoperiod days as pDays (versus earth days). I saw what I believe to be pistils last night during evening lights-on (pDay 7)

Ok guys, i'm a cheap bastard, so here's how you can do 730nm the cheapest I know possible (in regards to timers):

buy two of these:

either 12V or 5V powered cycle relay timer - it has 18 modes, and can do cycles up to from .1 second to 99*999 seconds. Search '12v relay cycle timer' on ebay or Aliexpress to find them for < $10.

Run both on the same power supply so that you have 2 timers using the same power source (this is for them to operate, not the juice provided to the devices for which you are going to use the relay).

You would set the 'main light' timer to be OFF by default (for the dark period time)
You would set the '730nm light' timer to be ON by default (for 7-10 minutes)

This way, if you lost and regained power, it would start in the dark cycle and put the plants to sleep. You do have to program the two timers (not that hard), but once done, if you use the same power source for both, you don't have to worry about them getting out of sync.

Note, I bought 1 of these to play with - I'm not using it yet. If anyone wants the script source for my rpi timer that I am using, I'd share it.

Here's a basic explanation of my rpi based timer. Because I'm testing a 12 hr cycle, which fits into a 24hr period perfectly, I'm not yet having to do anything difficult for time-keeping. My script just has run time arguments - On, Off, Verify:

On: sets a status flag, turns the main light relay on
Off: sets status flag, turns the 730nm light on, turns the main light off, counts down 7 minutes, then shuts down the 730nm.
Verify: checks status flag, and makes sure that the light's are running according to the status

I run verify every hour mark that I'm not turning things on or off. On hour marks that are triggering on or off, I run verify 10 minutes after the hour to make sure the things are as they should be. I also run verify on powerup, to recover from power fail and revert to the state it was last in.

If 12 hour day cycles don't work out and I need to test other ones, my script will have to evolve a bit to handle the odd schedule.

earth day 7, pDay 14, definitely not as far along as I would have hoped. The plant is growing and in general good health, so I guess it's happy with the container/nutes/air situation. The pistils appear to have swollen some and have changed color - I don't remember this being part of the normal early flowering stage so it's got me a bit perplexed.