Self-made LED panel general discussion

PetFlora

PetFlora

Well-Known Member
Let me use this analogy:

If you've only ever eaten average steak, you would not know how wonderful an organically grown grass fed steak tastes. Hell you might not even appreciate it.

It seems you are content with where you are on the importance of 500-600. So be it.

As they say in Texas, you can lead a horse to water but you can't make it drink.
 
Gastanker

Gastanker

Well-Known Member
If we are throwing out spectral absorption patterns because they are based on spinach, tomato, and lettuce, than can we really say that LEDs manufactured to grow lettuce are any good for bud? Not at all trying to bash illumatex but to assume that they are great because they grow lettuce large scale seems a bit off.
 
Rasser

Rasser

Active Member
PetFlora said:
Let me use this analogy:

If you've only ever eaten average steak, you would not know how wonderful an organically grown grass fed steak tastes. Hell you might not even appreciate it.

It seems you are content with where you are on the importance of 500-600. So be it.

As they say in Texas, you can lead a horse to water but you can't make it drink.
Click to expand...

Please we are talking about a spectrum of light, not taste or eating with good conscience.

No I'm not content, I've just not see any evidence that green light should have any special purpose.
 
Rasser

Rasser

Active Member
jubiare said:
FROM KNNA THREAD, SOMETHING IMPORTANT ABOUT THE PHOTONS

Photosynthesis is tightly linked with total amount of photons absorbed. This concept is the base of all, and it should be clear for any grower. So im going to analyze it deeper:

-Amount of photons. Not of watts, or lm. Plants use photons, so the number of photons is the essential figure to consider. The more the photons which reach the plant, the better (up to a limit).

Its important to note that same energy (for example 1 watt) of blue (450nm) have 33% less photons than of red ones (670nm) (450/670=0.67 : as noted before, energy carried by a photon is inversely proportional to its wl) if we take the amount of red photons as base. If we take the amount of blue photons as reference, then 1 watt of red ones carries 49%, near half, more photons (670/450=149). So very often, producing as more red photons possible is the most effective way of using artificial light for growing plants (if the efficiency of producing 1 watt of each are similar).
Click to expand...
I'm not following your ways of dividing the wavelength to get results.

Could you please look at this page, where there is a WL vs. Ev calculator.
http://www.pveducation.org/pvcdrom/properties-of-sunlight/energy-of-photon

When using that, there is this difference in energy between the to states of vibration.
A red photon with WL of 660nm have a energy of 1.879 eV
A blue photon with WL of 442nm have a energy of 2.808 eV

I see it as getting hit by a heavy weight(blue) vs. a light weight(red)
a blue led sends out fewer punches but is hitting 35% harder than red.

That I could not see in your calculations.
 
Rasser

Rasser

Active Member
Gastanker said:
If we are throwing out spectral absorption patterns because they are based on spinach, tomato, and lettuce, than can we really say that LEDs manufactured to grow lettuce are any good for bud? Not at all trying to bash illumatex but to assume that they are great because they grow lettuce large scale seems a bit off.
Click to expand...
I can't find any specific Cannabis plants absorption charts, and since most green leaf plant charts looks the same
one could assume that the spectrum is the same for both plants but maybe the intensity nedded for cannabis is a magnitude larger.

This one from NASA looks interesting.
 
jubiare

jubiare

Active Member
from that grapht I am afraid you cannot say "green isn't beneficial for tomato growing" sorry.

It is beneficial at his best at 15%, that's what we see from that

and anyway that's not the full story, but it's something to consider
 
jubiare

jubiare

Active Member
there is things to consider guys, from facts and good analysis.

HGL (don't care about the company what I care is the results) is currently using 15% green 10% blues 75% reds, this thread is on an other board and verdantgreen (the grower) has archived 1.21g/w




Things like that you want to consider, just consider
 
jubiare

jubiare

Active Member
Rasser said:
I'm not following your ways of dividing the wavelength to get results.

Could you please look at this page, where there is a WL vs. Ev calculator.
http://www.pveducation.org/pvcdrom/properties-of-sunlight/energy-of-photon

When using that, there is this difference in energy between the to states of vibration.
A red photon with WL of 660nm have a energy of 1.879 eV
A blue photon with WL of 442nm have a energy of 2.808 eV

I see it as getting hit by a heavy weight(blue) vs. a light weight(red)
a blue led sends out fewer punches but is hitting 35% harder than red.

That I could not see in your calculations.
Click to expand...
That was knna thread, it would be nice to have a clarification from him .. difficult to find him around those days

have you read the whole article?

From what is my understanding, the fact that the blue has more "energy" that's for sure ... but the majority of the sun usable photons come from the 670nm, more than any other wl. So plants have adapted to that, of course, for growing.

More energy blue (more watts) doesn't mean more usable photons?
 
Rasser

Rasser

Active Member
jubiare said:
from that grapht I am afraid you cannot say "green isn't beneficial for tomato growing" sorry.

It is beneficial at his best at 15%, that's what we see from that

and anyway that's not the full story, but it's something to consider
Click to expand...
But you can say that if you got 100 watts of light, how do you want to distribute that?

using 20-60-20 and get 95g/m2 on 120 days or
using 10-15-75 and getting 185g/m2 on 100 days

What will happen when using 20-0-80 that is the question.
Green light may be the lubricant that makes things run smooth,
I've just not seen any evidence for that.

What I think is missing from most LED grows is intensity,
like in this test grow of a 90W(70W actual) UFO vs. a 400 watts HPS (430W actual)
70 Watts to replace 430 Watts that would be to good to be true.








The user is rating it like this:
LED wins on low energy consumption, but makes popcorn.
HPS wins on bud size and there firmness.
Taste is bit different, the HPS larger buds have longer drying time.
smell or potency is equal.
 
Rasser

Rasser

Active Member
jubiare said:
That was knna thread, it would be nice to have a clarification from him .. difficult to find him around those days

have you read the whole article?
Click to expand...
No I thought it was your calculations.
I will search for it.

From what is my understanding, the fact that the blue has more "energy" that's for sure ...
but the majority of the sun usable photons come from the 670nm, more than any other wl.
So plants have adapted to that, of course, for growing.
Click to expand...
I don't quite get it, both chlorophyll a & B have spike's at red an blue
and the absorption in the blue is higher.


More energy blue (more watts) doesn't mean more usable photons?
Click to expand...
Making a blue photon takes 2.8Ev where a red only takes 1.8Ev
so off course using 1W of electricity there is more photons coming out of a red LED than a blue one.
but the impact of the chlorophyll from a blue photon should be larger and produce more energy than a red one.

I'm thinking about the human skin, where visible light have no biological effect, but high energy UV has
the power to interact with the pigment and make vitamin D, and going higher
alpha(helium nuclei), beta(electrons) and gamma(high frequency photons) rays have the power to mess with the DNA of the cell.

Maybe blue light work in a deeper layer of the leaf than red.
 
jubiare

jubiare

Active Member
perhaps better to use something like this? the article (thread) is Needed lighting concepts to develop LED grow lights

 
P

patrikantonius

Active Member
jubiare said:
Look at the productivity of Tomato (similar to MJ, better than cucumber one) under this research

http://biology.mcgill.ca/Phytotron/LightWkshp1994/1.4 Prikupets/Prikupets text.htm
Click to expand...
Wanted to bump on this post, in this study : http://www.lzi.lt/tomai/97(2)tomas/97_2_tomas_str10.pdf, done in 2010 with LEDs on tomato plants, the results are the following:
for dry weight, from best to worst:
1) uv + red + blue
2) red + blue
3) red + blue + green
3) red + blue + yellow
4) red + blue + orange
I like to think that UV has little to no effect on marijuana (I cannot source this, but I think I remember reading that from a forum where knna did post, plus UV has several downsides and good reasons not to be used) so if the first result is removed the best efficiency is made with only red and blue LEDs.
 
P

patrikantonius

Active Member
Rasser said:
Making a blue photon takes 2.8Ev where a red only takes 1.8Ev
so off course using 1W of electricity there is more photons coming out of a red LED than a blue one.
but the impact of the chlorophyll from a blue photon should be larger and produce more energy than a red one.

I'm thinking about the human skin, where visible light have no biological effect, but high energy UV has
the power to interact with the pigment and make vitamin D, and going higher
alpha(helium nuclei), beta(electrons) and gamma(high frequency photons) rays have the power to mess with the DNA of the cell.

Maybe blue light work in a deeper layer of the leaf than red.
Click to expand...
I think what Knna meant is that the energy of each photon is not relevant and what's relevant is the total number of photons hitting the plant. I hate to say this but it seems to have become common knowledge that a majority of red light is more beneficial to the plant than a majority of blue. I have not seen successful growths of marijuana using only blue light while the opposite is true.
 
bassclef

bassclef

Active Member
Rasser said:
I don't quite get it, both chlorophyll a & B have spike's at red an blue
and the absorption in the blue is higher.
Click to expand...
I remember seeing somewhere that these graphs aren't exactly accurate representing the peaks of each wavelength in ratio. It's also different for each plant, so these PAR graphs are more of a general guide rather than a rule. I don't think there is a definitive one for cannabis. I remember reading a study where they tested a number of plants and the red peak was greatest around 600-660nm in most of them. The blue peaks were there, but much lower. I'll try to find it.
 
jubiare

jubiare

Active Member
well, interesting .. I think it says it was carried in 2007 ..

so from this, it's best not to use any green, yellow and orange, especially orange as it inhibited growth (tomato)

what about when you use a white that encompass IR green and all? :D




 
Rasser

Rasser

Active Member
But is the above chart in post #93 complete, I seen carotenoid is included on some charts.

http://en.wikipedia.org/wiki/Carotenoid

Carotenoids are tetraterpenoid organic pigments that are naturally occurring in the chloroplasts and chromoplasts
of plants and some other photosynthetic organisms like algae, some bacteria, and some types of fungus.

There are over 600 known carotenoids; they are split into two classes, xanthophylls (which contain oxygen)
and carotenes (which are purely hydrocarbons, and contain no oxygen).

Carotenoids in general absorb blue light.
They serve two key roles in plants and algae: they absorb light energy for use in photosynthesis, and they protect
chlorophyll from photodamage.[SUP][2][/SUP]

In oxygenic photosynthetic organisms, specifically flora and cyanobacteria, the carotenoid β-carotene plays a vital role in
the photosynthetic reaction centre where, due to quantum mechanical reasons arising from the symmetry of the molecule,
it provides a mechanism for photoprotection against auto-oxidation. They also participate in the energy-transfer process.
In non-photosynthesizing organisms, such as humans, carotenoids have been linked to oxidation-preventing mechanisms.
Click to expand...

http://en.wikipedia.org/wiki/Photosynthetically_active_radiation
Chlorophyll, the most abundant plant pigment, is most efficient in capturing red and blue light.
Accessory pigments such as carotenes and xanthophylls harvest some green light and pass it
on to the photosynthetic process, but enough of the green wavelengths are reflected to give
leaves their characteristic color. An exception to the predominance of chlorophyll is autumn,
when chlorophyll is degraded (because it contains N and Mg) but the accessory pigments are not
(because they only contain C, H and O) and remain in the leaf producing red, yellow and orange leaves.
 
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