Viceman666
Well-Known Member
I think I read that leaf temp should be about 82F for white LED(a little more than the 80F for hps) for maximum photosynthesis as they produce less heat than hps.. dont quote me on that but worth taking a look
Extreme Flowering Under Pair of Timber 48SAMS
- Thread starter Or_Gro
- Start date
Or_Gro
Well-Known Member
Info i read is that max photosynthesis is at 86F airtemp (w/ 1500ppm co2). Leaf temp, tho, would be better measure; but if 86 airtemp is peak photosynthesis, i’d expect peak leaf temp to be somewhere near there.
[can’t wait for canada to start doing basic research on cannabis at universities, until reef is delisted from sched1 in US, won’t get much here. I’m a commercial grower of a diff crop, we had this basic shit nailed down 50-100 yrs ago.]
Was fighting temp yesterday, high humidity day and controller was driving down humidity faster than temp could recover. Could only avg 80F at 62.5% trigger.
Threw some moving blankets over tent (already had cardboard around 3 sides), and fired up a radiator heater. Should nail 83-84 today, save 86 for when i get ppfd up to 1350.
My floor is cold, but buckets on wheels, so watching water temp closely, 73F this morning.
Don’t really want to get into setting up a recirc manifold system for my water cooler, but also don’t wanna give up my wheels (spinning plants 180 each day).
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Or_Gro
Well-Known Member
3 tallest plants stretching ~2” per day, now 18-19” above res lid - if this continues plants will be at least 4’ tall by end of stretch.
Put a plastic bin under shortest plant, to raise it up to same ppfd level (1000-1100; DLI low 50s) as others.
Diesels a little shorter and more compact than hazes.
Lightson temp ranging 82.5-84.5, rh triggering fan at 65%, finally! Will start focusing on lightsoff temps & rh.
CO2 holding at/above 1500ppm.
All plants drinking about 1.5 quarts/day. EC dropping 0.1-0.2 per day; pH dropping 3-4 tenths per day.
Pistils developing at nodes and tips - still have to look for them, but they’re comin in. Since lightsoff is just 10.5hrs, far red initiator must be doing its job.
Rest of emerson boards arriving today, hopefully hang them tomorrow, won’t go lightson until after stretch - plenty of photosynthesis currently, don’t need to risk adding to stretch.
Put a plastic bin under shortest plant, to raise it up to same ppfd level (1000-1100; DLI low 50s) as others.
Diesels a little shorter and more compact than hazes.
Lightson temp ranging 82.5-84.5, rh triggering fan at 65%, finally! Will start focusing on lightsoff temps & rh.
CO2 holding at/above 1500ppm.
All plants drinking about 1.5 quarts/day. EC dropping 0.1-0.2 per day; pH dropping 3-4 tenths per day.
Pistils developing at nodes and tips - still have to look for them, but they’re comin in. Since lightsoff is just 10.5hrs, far red initiator must be doing its job.
Rest of emerson boards arriving today, hopefully hang them tomorrow, won’t go lightson until after stretch - plenty of photosynthesis currently, don’t need to risk adding to stretch.
Or_Gro
Well-Known Member
Whackamo! Nailed lightson air temp, fucked up water temp...finally had to take off my wheels when water temp rose to 80F, my cold floor cooled it down to 70F.
Getting pretty dense canopy, blocking light and airflow, took off bottom 2 pairs of fan leaves on each main, which have done their primary job of signaling and providing energy to push tips in their axils. Would like to drop more, but will proceed slowly for now.
Checked far red initiator at lightsoff, cycle timer clicking light on/off every few seconds. Looks like small, green leds on fan were enuff to confuse the light sensor on timer. Covered leds and repositioned sensor, will check again tonight. Looks like it doesn’t take much far red to put plants to sleep, cuz pistils continue to form w only 10.5 hours of lightsoff.
7-8 node pairs, w laterals, on each main at this point, tips 19-20” above res lid.
Getting pretty dense canopy, blocking light and airflow, took off bottom 2 pairs of fan leaves on each main, which have done their primary job of signaling and providing energy to push tips in their axils. Would like to drop more, but will proceed slowly for now.
Checked far red initiator at lightsoff, cycle timer clicking light on/off every few seconds. Looks like small, green leds on fan were enuff to confuse the light sensor on timer. Covered leds and repositioned sensor, will check again tonight. Looks like it doesn’t take much far red to put plants to sleep, cuz pistils continue to form w only 10.5 hours of lightsoff.
7-8 node pairs, w laterals, on each main at this point, tips 19-20” above res lid.
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Or_Gro
Well-Known Member
Got my additional HLG 35 emerson boards, too burnt to put them up, they’ll be up by time i need them, w pics of that beautiful red light.
Jesus, the driver plugin on these things is delicate!!! I busted one off hangin the first pair, didn’t even get the second pair out of the bubble wrap and another one fell off.
Soldered it back on, looks like shit but works.
HLG are great people, and i can’t wait to use these boards, but they really need to protect that plugin!!!
Beware! It’s held on by those four solder points, and can’t take any side pressure.
Jesus, the driver plugin on these things is delicate!!! I busted one off hangin the first pair, didn’t even get the second pair out of the bubble wrap and another one fell off.
Soldered it back on, looks like shit but works.
HLG are great people, and i can’t wait to use these boards, but they really need to protect that plugin!!!
Beware! It’s held on by those four solder points, and can’t take any side pressure.
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Randomblame
Well-Known Member
Can't wait to see the final fixture. Plants seems to like the light and already have a strong base.
Do you accept bets which will be the tallest, lol?
Do you accept bets which will be the tallest, lol?
Or_Gro
Well-Known Member
My money’s on the back right one, 22-23” this morning.
But how about guesses on what day 21 height is (yesterday was day 7) for tallest plant?
I’ll guess 50”, 127cm.
I’m surprised at how even each plant is, so far, without much effort on my part. Shows the power of evenly spread, high intensity light.
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Or_Gro
Well-Known Member
Beginning of week 2, removed 3rd pair of fan leaves from bottom of each main (3 of 4 original pairs now removed). Air & water temps, rh, pH, ec all in range. Running 1100 ppfd, 20” above tallest plants, 13.5hrs on/10.5 off. Plants drinking 1.5qts/day.
NYC Diesels on left (front one on pedestal so it gets same ppfd as others), Super Silver Hazes on right. Back right plant is tallest (22-23” above res lid).
NYC Diesels on left (front one on pedestal so it gets same ppfd as others), Super Silver Hazes on right. Back right plant is tallest (22-23” above res lid).
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Or_Gro
Well-Known Member
All reds up and ready to grow some ginormous colas.
Far Red Bar: currently running for first 15 mins after lightsout
HLG QB-35 Emerson Boards: Four of them mounted in offset pairs on each Timber 48sams, will be running for full lightson once stretch is done.
Far red bar is also on (never will be on when other lights are on), but relative intensity perceived by human eyes is too low to see when other lights are on.
Far Red Bar: currently running for first 15 mins after lightsout
HLG QB-35 Emerson Boards: Four of them mounted in offset pairs on each Timber 48sams, will be running for full lightson once stretch is done.
Far red bar is also on (never will be on when other lights are on), but relative intensity perceived by human eyes is too low to see when other lights are on.
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Or_Gro
Well-Known Member
The following article (referred to as “Chandra”) is the basis for ppfd, temp, and co2 limits in this grow.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550641/pdf/12298_2008_Article_27.pdf
It is the best cannabis-specific basic research that i am aware of.
The primary conclusions of this study are that peak photosynthesis occurs at ~1500ppfd and 30C/86F.
I and others are concerned that due to the methods used wrt light intensity (i.e. plant leaf photosynthesis measurements made after only about 30min exposure to different ppfd levels), the research does not adequately deal with daily light integral (dli); additionally, measurements were done w/o respect to diffs in veg/flower developmental stage.
DLI (daily dosage of ppfd) is an important consideration when focusing on optimal light intensity for photosynthesis. Most growers recognize that plants can handle extremely high light intensity (high ppfd) for short periods of time, but longer term extreme intensity (high dli) causes, at a minimum, bleaching/burn damage.
It is important to recognize that the1500ppfd (chandra’s optimal intensity) for common flowering lightson period of 12 hours equates to 65dli, which is the intensity of sunlight inPhoenix, AZ during a sunny summer day.
Studies of dli across the US (see https://www.extension.purdue.edu/extmedia/ho/ho-238-w.pdf) show that dli in northern california/southern oregon (primo outdoor cannabis growing region) is significantly less than 65dli (ranging 40-55 during may-june veg period; 30-45 during aug-sept flowering period; 20-25 during oct harvest period).
The evidence of “light burn” in this grow is indicating, at least for early flowering period, that the natural dli of norcal/sooreg is more tolerable, and therefore much more likely to be closer to optimal, than chandra’s results.
Current dli in this grow is somewhere near 50dli (13.5 hours @ 1050 ppfd, equiv of 12 hours @approx 1160 ppfd).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550641/pdf/12298_2008_Article_27.pdf
It is the best cannabis-specific basic research that i am aware of.
The primary conclusions of this study are that peak photosynthesis occurs at ~1500ppfd and 30C/86F.
I and others are concerned that due to the methods used wrt light intensity (i.e. plant leaf photosynthesis measurements made after only about 30min exposure to different ppfd levels), the research does not adequately deal with daily light integral (dli); additionally, measurements were done w/o respect to diffs in veg/flower developmental stage.
DLI (daily dosage of ppfd) is an important consideration when focusing on optimal light intensity for photosynthesis. Most growers recognize that plants can handle extremely high light intensity (high ppfd) for short periods of time, but longer term extreme intensity (high dli) causes, at a minimum, bleaching/burn damage.
It is important to recognize that the1500ppfd (chandra’s optimal intensity) for common flowering lightson period of 12 hours equates to 65dli, which is the intensity of sunlight inPhoenix, AZ during a sunny summer day.
Studies of dli across the US (see https://www.extension.purdue.edu/extmedia/ho/ho-238-w.pdf) show that dli in northern california/southern oregon (primo outdoor cannabis growing region) is significantly less than 65dli (ranging 40-55 during may-june veg period; 30-45 during aug-sept flowering period; 20-25 during oct harvest period).
The evidence of “light burn” in this grow is indicating, at least for early flowering period, that the natural dli of norcal/sooreg is more tolerable, and therefore much more likely to be closer to optimal, than chandra’s results.
Current dli in this grow is somewhere near 50dli (13.5 hours @ 1050 ppfd, equiv of 12 hours @approx 1160 ppfd).
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Or_Gro
Well-Known Member
The following article is one of the best reviews of red & far red light that i have come across, this copy was posted by fellow grower randomblame in another thread.
Although not specific to cannabis, the article shows the tremendous amount of research that is the basis for the manipulation of plants using red & far red spectrum in commercial horticulture.
In this grow, far red is being used to shorten lightsoff period to 10.5 hours, by triggering nighttime processes almost immediately (versus normal 2hr ramp) after a 15min dose of far red at lightsout.
After stretch phase is completed, red & far red lights will be used to supplement the timber QBs, to more fully & efficiently utilize photosystems I & II.
Although not specific to cannabis, the article shows the tremendous amount of research that is the basis for the manipulation of plants using red & far red spectrum in commercial horticulture.
In this grow, far red is being used to shorten lightsoff period to 10.5 hours, by triggering nighttime processes almost immediately (versus normal 2hr ramp) after a 15min dose of far red at lightsout.
After stretch phase is completed, red & far red lights will be used to supplement the timber QBs, to more fully & efficiently utilize photosystems I & II.
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Or_Gro
Well-Known Member
The future of grow lights is in tunable spectrum.
Intensity, efficiency, and heat control are old news...they are necessary, but not sufficient!
Or_Gro
Well-Known Member
How iphone camera without flash sees plants at far red sleepytime:
How an iphone camera with flash sees plants at far red sleepytime:
How a human eye sees plants at far red sleepytime:
Imagine the following pic bathed in dark, ruby red light (like first pic above), with all the plant leaves in clear focus, but the color of red poinsettias.
Frickin beautiful!
How an iphone camera with flash sees plants at far red sleepytime:
How a human eye sees plants at far red sleepytime:
Imagine the following pic bathed in dark, ruby red light (like first pic above), with all the plant leaves in clear focus, but the color of red poinsettias.
Frickin beautiful!
Ziggyman22
Member
Looking great BEAUTIFUL
Or_Gro
Well-Known Member
Thanks man!
Or_Gro
Well-Known Member
Day 11: Removed another pair of fan leaves (4th active node from bottom on each main), tallest plant (back right haze) 29”-30”, both front plants now on pedestals to provide same ppfd to tips under each fixture. All controlled variables in range. ~1050 ppfd at tallest tips below each fixture.
Or_Gro
Well-Known Member
Day 12:
Hazes (right) stretching 2”/day, back 31-32”, 10 active node pairs; front (on pedestal) 26-27” 9 active node pairs. Removed pair of fan leaves (5th active node from bottom) and one short lateral from each main. Need to open canopy, but trying not to screw up stretch.
Diesels hardly stretching (surprising since both strains are “tall” ones w similar stretch), back 22-23”, 9 active node pairs; front (on pedestal) 18-19”, 8 active node pairs.
Lightson air temp ~82-83F, rh ~60-62%, ppfd ~1050 at highest tip each left/right fixture 13.5 on:10.5 off, far red on 1st 15 min lightsoff, water temp 73-77F (clear, no smell, roots snowwhite), pH 6.1, ec 2.0, 3 circ fans running high speed, C02 1500ppm lightson.
Hazes (right) stretching 2”/day, back 31-32”, 10 active node pairs; front (on pedestal) 26-27” 9 active node pairs. Removed pair of fan leaves (5th active node from bottom) and one short lateral from each main. Need to open canopy, but trying not to screw up stretch.
Diesels hardly stretching (surprising since both strains are “tall” ones w similar stretch), back 22-23”, 9 active node pairs; front (on pedestal) 18-19”, 8 active node pairs.
Lightson air temp ~82-83F, rh ~60-62%, ppfd ~1050 at highest tip each left/right fixture 13.5 on:10.5 off, far red on 1st 15 min lightsoff, water temp 73-77F (clear, no smell, roots snowwhite), pH 6.1, ec 2.0, 3 circ fans running high speed, C02 1500ppm lightson.