LED's make Less Heat. Do plants Yield more in Higher Heat?

[MeanBean]

I look forward to your led show head, do you plan to use a production model light or is it something you are designing?

The details are in my sig... but I am using 1 126 Watt Penatrator 2ng gen.

 

[MerryPrankstr]

Please re-read my post!

Please re-read my post!

I am NOT bashing LEDs I grow with them exclusively.
I also have a LOT of experience growing with them successfully.
Your answer concerning temperatures is at the end, BTW.
M.P.

 

[Grat3fulh3ad]

I look forward to your led show head, do you plan to use a production model light or is it something you are designing?

to be announced =]

 

[secondtry]

All though I do apreciate the point of view of Bulb growers!!

That's like me asking how do I get around in a wheelchair and you telling me to shut up and walk... not gonna happen. HELP me in the situation I am in.... LED

In that thread there are people using low wattage UV fluoros from the medical industry, and we calculated the correct distances for correct irridances. I fyou read that thread you should be able to learn all you need to and find a great UV lamp you can use. I was only stating what I use, not that it's has to be used.

HTH

 

[Grat3fulh3ad]

So... show me the ppfd statistics which back up your assertion that LED lights have a lower Pn than HIDs.


do you not imagine that the ppfd is a function of PAR luminosity?

Obviously the greater percentage of a light source's luminosity falls within PAR range (favoring peaks), the greater the Pn per watt of energy used.

 

[MerryPrankstr]

Construction of said lamps including parts lists and schematics:

http://boards.cannabis.com/indoor-lighting/167881-calling-out-weezard-led-advice-2.html

Photos of Sunlight vs LEDs in Weezard's album.

He is a member of ICMag, and will answer any questions. We are both old retired farts.

M.P

 

[secondtry]

If you are trying to grow with 1 watt emitters (a la LED Girl's lamps) they will perform marginally at best. Not trying to put her down, it's just that these are cheaper LEDs that don't have the output needed to flower robustly like in natural daylight. LED Girl would serve herself and the community better by moving on to the newer, more powerful technology ( i.e. 15 and 45 watt emitters), but when suggestions of this nature were made to her, she has abruptly deleted all such threads. Too bad! We are just trying to help her develop her product and help others.

With 2 or 3 watt emitters, we actually start to see some real good flowering and at 5 watt emitters we have an even output in photonic flux to match HPS and MH lamps. With the newest 15 watt emitters one actually gets so much light output that it is equal to the sun at noon in a tropical latitude.

Dude, you need to read up, we don't measure photonic flux, we measure PPFD. And you didn't mention distance, that is the determining factor of PPFD (irridiance); further away from canopy = less PPFD; closer to canopy = more PPFD. See? That is why I state LEDs need to be close to the canopy to provide proper PPFD.

And the bit about "equal to the sun at noon in a tropical latitude" IS PPFD at 1,500. That is why it was used as a starting point for testing PPFD effects upon Pn. So, to recap: ideal PPFD = 1,300-1,500. But, one must measure the PPFD with a quantum sensor, Li-Cor is the company to buy from.

Tests made by a friend who is a legal Hawaiian Med Grower were conducted to compare his latest build against natural tropical sunlight, and the LEDs outperformed sunlight!

Can I see the test results please? I happen to well versed in light quantum physics and photosystems of higher plants, along with photo-biological reactions. I would love to see how he came to these conclusions...as would ALL icmag readers I bet...

Back to the original question

, I have found that the best growth was obtained at 80-85 F temps during the day, but I got better F to M ratios from seed keeping my grow at 75-78 F.

M.P.

That temp for seed to effect MF ratios is not correct AFAIK, and it's from Dutch Passion too boot IIRC. It has been shown that cannabis does not "differentiate" sexually until the the leaf of the 4th node appears (I can offer reference to white paper), around a few weeks. Before that there is little effect of environ on MF ratios; it's genetic for the most part.

 

[secondtry]

So... show me the ppfd statistics which back up your assertion that LED lights have a lower Pn than HIDs.

PPFD is more about distance than power (watts), and PPFD is also about the nanometers (SPD) emitted by the lamp; that said, PPFD is a measure of time (second) so a lamp with higher power which emitted more photons offers higher PPFD simply by the laws of physics. Also, PPFD is emitted per nanometer, so I hope this illustrates the limited PPFD of LEDs: a LED with 2-3 nanometers emitting PPFD vs. a HID with over 300 nanometer emitting PPFD.

do you not imagine that the ppfd is a function of PAR luminosity?

No. PAR is not luminosity. PAR is a qualification and PPFD is a quantificiation. PAR identifies the spectrum and PPFD counts the photons; two different functions which are dependent upon each other to make use light measurements, but PPFD is not a function of PAR.

Obviously the greater percentage of a light source's luminosity falls within PAR range (favoring peaks), the greater the Pn per watt of energy used.

Yes! That's (basically) my whole point. LEDs only offer a few nanometers in PAR while HIDS offer ALL of PAR, both attempting to offer highest PPFD at nanometers offering highest Pn within PAR. Thus, HID offers more Pn than LEDs on a one to one basis (as if we used a 100 watt HID and 100 watt LED). But, considering there is so much more power from a HID it means there is more PPFD within PAR thus further increasing Pn to it's maximum or ideal. I know you will say: but, LEDs offer ALL their irridance (not luminance) in blue and red PAR. And you would be correct, but the irridiacne offered (PPFD) of those nanometers in PAR from LEDs is too low (for peak Pn) at the average distance LEDs are hung. Also, as I wrote red and green PAR photons (PPFD) offer more photosynthesis than blue PAR, thus on a nanometer by nanometer basis HIDs emit way more photons (in green and red PAR) which drive photosynthesis up to 2-3x the rate blue PAR photons (PPFD) do!!!

 

[MerryPrankstr]

Secondtry,
Please use your powers of observation to read the material at the link above your reply. It contains the beginning of a thread that will answer your questions.

Let's try to discuss, not argue...
I remember when I started growing cannabis indoors about 30 years ago. People gave me all the same kind of excuses why it simply could not work. After all we had been doing it outdoors and in greenhouses. No way a lamp could grow cannabis without sunlight. It needed to much light.

It's Deja Vu, all over again....

The Idea is to keep an open mind and actually do experimentation and not just parrot things we have read. Reading is only the first step of research, right?

M.P.

 

[secondtry]

Hey MP,

I am not arguing, maybe a little tense after the slight barrage of attacking posts, but not arguing.

I agree about an open mind, and I wish the LED crowd would apply that to light quantum physics and photosystems of higher plants. I plan to carry out plenty of research but as I've written many times, I first need to buy the tools; one can't just grow cannabis and make a valid conclusion without analytical quantitation, as such I am buying a chlorophyll fluorometer, reflectance spectroscopy setup, more quantum sensors, etc. Without those basic tools, totaling over about $20,000 one can't expect a analytically valid conclusion.

But it doesn't matter for us, because all the research has already been carried out, it's just locked in the vaults of academia, to which I have full access. Why try to figure something out which people whom are much better qualified, funded and supported have already done so? Cannabis is not special, it responds very similarly to other C3 higher green plants to light stimuli. And the aspects of light quantum physics I wrote about are also valid; I have already shown you why LEDs are inferior using physics facts and solid science...why don't you accept that?

P.S. I asked for reference before you posted that, I think we cross-posted. If at last a quantum sensor was not used then I am probably not going to be interested

 

[Grat3fulh3ad]

PPFD is more about distance than power (watts), and PPFD is also about the nanometers (SPD) emitted by the lamp; that said, PPFD is a measure of time (second) so a lamp with higher power which emitted more photons offers higher PPFD simply by the laws of physics. Also, PPFD is emitted per nanometer, so I hope this illustrates the limited PPFD of LEDs: a LED with 2-3 nanometers emitting PPFD vs. a HID with over 300 nanometer emitting PPFD.

I know. PAR = "the best nanometers". Radiation who's wavelength (not nanometers, though wavelength are sometimes measures in nanometers) does not fall within PAR range are wasted energy. SPD is simply the lamps spectral output. most of a HPS lamp's SPD falls outside of peak PAR range.

BTW... it is funny that you say an LED only emits 2 or 3 nanometers.

What you meant to say (I hope) is that LED arrays generally only emit 2 or 3 wavelengths.

If you think lamps emit nanometers of light, you are more confused than I originally thought.

Let me help you get unconfused.... Lamps emit radiation of different wavelengths. these wavelengths are discribed by the measurement of the distance between periods, with PAR wavelengths being of a size which is measured in nanometers.

No. PAR is not luminosity. PAR is a qualification and PPFD is a quantificiation. PAR identifies the spectrum and PPFD counts the photons; two different functions which are dependent upon each other to make use light measurements, but PPFD is not a function of PAR.

Re-read. I never said PAR was luminosity.

PAR is the portion of the spectrum. Luminosity is the amount of radiation.

PAR luminosity = amount radiation which falls within photosynthetic range.

it's not as complicated as you try to make it.

PPFD is 100% a function of par luminosity.

Yes! That's (basically) my whole point. LEDs only offer a few nanometers in PAR while HIDS offer ALL of PAR, both attempting to offer highest PPFD at nanometers offering highest Pn within PAR. Thus, HID offers more Pn than LEDs on a one to one basis (as if we used a 100 watt HID and 100 watt LED). But, considering there is so much more power from a HID it means there is more PPFD within PAR thus further increasing Pn to it's maximum or ideal. I know you will say: but, LEDs offer ALL their irridance (not luminance) in blue and red PAR. And you would be correct, but the irridiacne offered (PPFD) of those nanometers in PAR from LEDs is too low (for peak Pn) at the average distance LEDs are hung. Also, as I wrote red and green PAR photons (PPFD) offer more photosynthesis than blue PAR, thus on a nanometer by nanometer basis HIDs emit way more photons (in green and red PAR) which drive photosynthesis up to 2-3x the rate of blue PAR! Does

LEDS use the most efficient PAR wavelengths.
Most (60%) of the HID's energy is wasted producing non PAR luminosity(not luminance).

PN is lowest between 520 and 600 nanometers wavelength where HID light shoot most of their load.


The most applicable measure of Pn in an indoor garden is dry yield.

 

[Grat3fulh3ad]

luminosity |ˌloōməˈnäsətē|
noun ( pl. -ties)
• Physics the rate of emission of radiation, visible or otherwise.



luminance |ˈloōmənəns|
noun
• Physics the intensity of light emitted from a surface per unit area in a given direction.

 

[VerdantGreen]

I grow with LED's, yeah I know right?

My grow area stays coool. like 70 - 75... Just wondering if raising it to 85 would help..

Any input is welcome

hi MB. im pretty sure LEDGirl advised me that temps from 80-85 give best results

however the grow i have been showing with her tiny 63 watt unit has had temps 65-75 and still show very encouraging results so far

V.

 

[secondtry]

I know. PAR = "the best nanometers". Radiation who's wavelength (not nanometers, though wavelength are sometimes measures in nanometers) does not fall within PAR range are wasted energy. SPD is simply the lamps spectral output. most of a HPS lamp's SPD falls outside of peak PAR range.

No. PAR is a range of nanometers, which is the "length" of each "wave" (e.g. wavelength) from crest to crest or bottom to bottom. Nm (nanometers) outside of PAR do provide photosynthesis, e.g. 360-400nm; and "accessory pigments" of leaf absorb non-PAR PPFD and transfer the energy to chlorophyll A and/or B (the main leaf pigments who absorb PAR).

SPD is the spectral output (but graph can include irridiance as PPFD) of the lamp in the PAR range. Thus we need the SPD and the PPFD reading to 'judge' a lamp for it's ability to grow cannabis, better yet is to convert PPFD to Quantum Yield which weights each photon per nanometer with it's relative photosynthetic effect.

BTW... it is funny that you say an LED only emits 2 or 3 nanometers.

What you meant to say (I hope) is that LED arrays generally only emit 2 or 3 wavelengths.

No, I mean what I wrote. See above where I defined what wavelength means. Nanometer is used interchangeably with wavelength, and nanometer is the lenght of the wave; i.e. 1-2 nanometers is the same as saying 2 or 3 wavelengths, except nanometers is what academia uses, as do plant photo-physicists/biologists, i.e., everyone I have learned from. One can say the "400th nanometer" meaning the start of blue PAR, or one can say the "wavelength of 400nm" meaning the start of blue PAR; but not "400th wavelength", or "400 wavelength", only "blue wavelength" but that's not accurate to nanometer.

If you think lamps emit nanometers of light, you are more confused than I originally thought.

Really? Somehow I doubt it...snicker, snicker, snicker...see above.

Let me help you get unconfused.... Lamps emit radiation of different wavelengths. these wavelengths are discribed by the measurement of the distance between periods, with PAR wavelengths being of a size which is measured in nanometers.

No. Nanometer is wavelength. A "nano-meter" is the distance of one "wave-length" at a certain spectrum of PAR.

Re-read. I never said PAR was luminosity. PAR luminosity = amount radiation which falls within photosynthetic range.

PAR is the portion of the spectrum. Luminosity is the amount of radiation.[/quote]Irridiance is PPFD, NOT luminosity. Trust me, your making yourself look un-informed.

PPFD is 100% a function of par luminosity.

no it is not, I alredy explined that to you.

LEDS use the most efficient PAR wavelengths.

no they do NOT. Red PAR range is the most effective at driving Pn under LED, NOT blue. Blue offers the *least* Pn of all PAR ranges. HID offer large amounts of PPFD in the two most critical PAR ranges which drive Pn: green and red. So you see, LEDs are only offering 1/2 of what they claim in terms of Pn response to the SPD they emit. That is why LEDs have lower Pn than HIDs. Don't you see that? Photons in red PAR drives Pn at lesat 2-3x more than photons in blue PAR

Most (60%) of the HID's energy is wasted producing non PAR luminosity(not luminance).

So? It's like I originally sated, NASA is try to grow plants with the least energy, NOT the best plants...which would you prefer?

The most applicable measure of Pn in an indoor garden is dry yield.

No, the most applicable measure of Pn is Pn, dry yield has many variables, not least of which is what does "dry" mean? (in terms of % moisture content). Generally more useful than Pn is Pnnet (the net photosynthetic rate over a daylength), or "3-day Light Integral". One can use a chlorophyll fluorometer to quantitate Pn by quantiating the photons emitted by the leaf in IR (~760 nm or so)

 

[VerdantGreen]

.......
If you are trying to grow with 1 watt emitters (a la LED Girl's lamps) they will perform marginally at best. Not trying to put her down, it's just that these are cheaper LEDs that don't have the output needed to flower robustly like in natural daylight. LED Girl would serve herself and the community better by moving on to the newer, more powerful technology ( i.e. 15 and 45 watt emitters), but when suggestions of this nature were made to her, she has abruptly deleted all such threads. Too bad! We are just trying to help her develop her product and help others.

With 2 or 3 watt emitters, we actually start to see some real good flowering and at 5 watt emitters we have an even output in photonic flux to match HPS and MH lamps. With the newest 15 watt emitters one actually gets so much light output that it is equal to the sun at noon in a tropical latitude.

Tests made by a friend who is a legal Hawaiian Med Grower were conducted to compare his latest build against natural tropical sunlight, and the LEDs outperformed sunlight!

Back to the original question, I have found that the best growth was obtained at 80-85 F temps during the day, but I got better F to M ratios from seed keeping my grow at 75-78 F.

M.P.

hi MP have you actually grown anything under LEDGirls LED's or are you just presuming they wont work?
what you say above contradicts my research which says that 1 watt led's give out more for the energy used than higher watt LED's. im no expert though.

V.

 

[MerryPrankstr]

Believe me when I say I understand exctly what you mean...

Believe me when I say I understand exctly what you mean...

I am not one of the LED crowd.

I am a very long time grower who is breaking from lurking to change up my genetics (still running genetcics from circa 89-92 and thought I'd get some of today's best to update).

No axe to grind, nor agenda to push forward. In fact I'll probably revert back t lurking as I'm normally not a big poster here.

Originally posted by SecondTry

I agree about an open mind, and I wish the LED crowd would apply that to light quantum physics and photosystems of higher plants. I plan to carry out plenty of research but as I've written many times, I first need to buy the tools; one can't just grow cannabis and make a valid conclusion without analytical quantitation, as such I am buying a chlorophyll fluorometer, reflectance spectroscopy setup, more quantum sensors, etc. Without those basic tools, totaling over about $20,000 one can't expect a analytically valid conclusion.

But it doesn't matter for us, because all the research has already been carried out, it's just locked in the vaults of academia, to which I have full access. Why try to figure something out which people whom are much better qualified, funded and supported have already done so? Cannabis is not special, it responds very similarly to other C3 higher green plants to light stimuli. And the aspects of light quantum physics I wrote about are also valid; I have already shown you why LEDs are inferior using physics facts and solid science...why don't you accept that?

Again: Reading is only the first step in research. If Wilbur Wright followed your example we would all still be scoffing at the idea of air travel. Same with Edison and his inventions. The link will allow you to construct the proper hardware so you could recreate the experiment and measure to your heart's delight. That's the way science moves forward, by doing not just reading.


Well, enough for me.

You can grow with a candle and magnifying glass i that's what you believe is best and it won't matter one iota to me. I am a pragmatist, now that I have retired and left acedemia ( and BTW one of the largest US Biomed research centers was at my total disposal with electron microscopes, and every kind of other scientific instrument at my disposal including some prototype nuclear and magnetic devices.

Now that I'm retired I just grow for my own medical needs with top rank genetics. I just cracked some Rez Chemdog IX-III for the next generation of mothers for my personal use.

Good luck with your research!

M.P.

 

[secondtry]

I am not one of the LED crowd.

I am a very long time grower who is breaking from lurking to change up my genetics (still running genetcics from circa 89-92 and thought I'd get some of today's best to update).

No axe to grind, nor agenda to push forward. In fact I'll probably revert back t lurking as I'm normally not a big poster here.

Originally posted by SecondTry


Again: Reading is only the first step in research. If Wilbur Wright followed your example we would all still be scoffing at the idea of air travel. Same with Edison and his inventions. The link will allow you to construct the proper hardware so you could recreate the experiment and measure to your heart's delight. That's the way science moves forward, by doing not just reading.

The science has already been done, there is no need to redo it. Unless you are coming up with a new discipline of light quantum physics, and if so I'm all ears.

What I am going to do is carry out all these quantitations with cannabis, which has not been done in full. But that doesn't mean the currently accepted proven scientific theory on PPFD, PAR, QY, etc, is not valid, it's is; precisely valid. The "ASP" (Action Spectra of Photosynthesis) is very similar for most all higher green plants, cannabis included. That is why I say we don't need to carry out experiments with non-analytical conclusions. We just need to apply what is already been found, but yet to be understood by people like us, and than applied. What I am referring to is way more advanced than LEDs and trust me, I get hated on way more than LED people for suggesting we use PPFD and not lumens, or lux, etc; I get hated on my HID folks, T5 folks, CMH folks, CFL folks and LED folks! Lucky me!

I actually told someone last week I feel like the guys who first started growing indoors, they got hated on for doing something different. But in my case I am fully backed up with mathematical facts, data, and much science; basically a road-map. The guys who first started growing indoor were just winging it, I am not...

 

[MerryPrankstr]

Hi Verdant Green,

hi MP have you actually grown anything under LEDGirls LED's or are you just presuming they wont work?
what you say above contradicts my research which says that 1 watt led's give out more for the energy used than higher watt LED's. im no expert though.

I have grown with lamps spec'd identicall to her's. It' from LED's that are 2 generations old.

Not putting them down. They are not unique, but the same technology as UFO's in a better more powerful package. This is the "engine" that she speaks of. But there are already LEDs out there (and lamps using them if you actual research them) that perform much better.

Technology moves on, advertising and marketing not withstanding. It is important to know exactly what's out there in terms of technology advances. There are 50 watt emitters out there, but only available in white. That's 50 watts each LED, bro... They are using them in streetlights.

Anyway, I hope she sees the "light" and gets going on using the new LEDs. They kick some serous butt.

Just pointing to the next step, "Furthur" if you will.
The future is already here, let's catch up with it.
M.P.

 

[MerryPrankstr]

SecondTry,

Can you please point me to where the experimentation has been documented using the latest 15watt and 50 watt emitters are concerned? I would be very interested in reading it.

M.P.

 

[Grat3fulh3ad]

No. PAR is a range of nanometers, which is the "length" of each "wave" (e.g. wavelength) from crest to crest or bottom to bottom. Nm (nanometers) outside of PAR do provide photosynthesis, e.g. 360-400nm; and "accessory pigments" of leaf absorb non-PAR PPFD and transfer the energy to chlorophyll A and/or B (the main leaf pigments who absorb PAR).

NOPE. PAR is a range of wavelengths. wavelengths are measured in nanometers. Wavelength outside on the photosynthetically active range do NOT photosynthesize. If they did then they would be within the photosynthetically range. You're funny calling wavelengths nanometers... you are confused.

Once more... If it is radiation and it causes photosynthesis it is PAR.

I'll get you sorted, if you'll stfu and learn what you are missing...

I have a beard hair that is 25400 nanometers wide... it should be really bright, eh? lmao

SPD is the spectral output (but graph can include irridiance as PPFD) of the lamp in the PAR range. Thus we need the SPD and the PPFD reading to 'judge' a lamp for it's ability to grow cannabis, better yet is to convert PPFD to Quantum Yield which weights each photon per nanometer with it's relative photosynthetic effect.

Duh...

ppfd is still dependent on PAR luminosity.

No, I mean what I wrote. See above where I defined what wavelength means. Nanometer is used interchangeably with wavelength, and nanometer is the lenght of the wave; i.e. 1-2 nanometers is the same as saying 2 or 3 wavelengths, except nanometers is what academia uses, as do plant photo-physicists/biologists, i.e., everyone I have learned from. One can say the "400th nanometer" meaning the start of blue PAR, or one can say the "wavelength of 400nm" meaning the start of blue PAR; but not "400th wavelength", or "400 wavelength", only "blue wavelength" but that's not accurate to nanometer.

nanometer is not used interchangeable with wavelength.

I can measure many things in nanometers which do not have wavelength and are not radiation.... you are confused.

you are really confused.

one can say 400nm to describe a wavelength of 400 nanometers.
one cannot say 'the 400th nanometer of light'

use google if you do not believe me.

Really? Somehow I doubt it...snicker, snicker, snicker...see above.

reallly confused....

No. Nanometer is wavelength. A "nano-meter" is the distance of one "wave-length" at a certain spectrum of PAR.

NOPE... you are dead wrong.

A nanometer is one billionth of a meter.

A wavelength is the distance between wave crest.

radiation is defined by its wavelength which is measured in nanometers.

LEDs emit one wavelength. say 400nm... The radiation has a distance of 400nm from one wave crest to the next.
An LED array can contain LEDs of many different wavelengths.

An LED emitting light at 400nm, is not emitting 400nm, it is emitting light with a wavelength of 400nm.

Irridiance is PPFD, NOT luminosity. Trust me, your making yourself look un-informed.

trust me.
you are uninformed.

"Irridiance" is not a word.

Luminosity is the rate of emission of radiation.

Source : New Oxford American Dictionary.

PPFD is definitely a function of PAR luminosity.
How can radiant energy in an area without luminosity?
How can the amount of photosynthetically active radiation being emitted not determine the flux per area?

no it is not, I alredy explined that to you.

no they do NOT. Red PAR range is the most effective at driving Pn under LED, NOT blue. Blue offers the *least* Pn of all PAR ranges. HID offer large amounts of PPFD in the two most critical PAR ranges which drive Pn: green and red. So you see, LEDs are only offering 1/2 of what they claim in terms of Pn response to the SPD they emit. That is why LEDs have lower Pn than HIDs. Don't you see that? Photons in red PAR drives Pn at lesat 2-3x more than photons in blue PAR

yes they do.

LEDs are red and blue... green is the least photosynthetically active.... stop embarrassing yourself. Tech is passing up your antiquated ideas.

So? It's like I originally sated, NASA is try to grow plants with the least energy, NOT the best plants...which would you prefer?

balance. I do not live in a world of only extremes.

No, the most applicable measure of Pn is Pn, dry yield has many variables, not least of which is what does "dry" mean? (in terms of % moisture content). Generally more useful than Pn is Pnnet (the net photosynthetic rate over a daylength), or "3-day Light Integral". One can use a chlorophyll fluorometer to quantitate Pn by quantiating the photons emitted by the leaf in IR (~760 nm or so)

Nope. dry yield tells 100% of the relevant story.

thanks for playing.