LED wavelength/spectrum graph questions

[Homesteader]

Did not know that. Temps also play a role. Anthocyanins don't do as well over 70f like photosynthesis. That's why people drop their temps to bring out color

When you increase the intensity of light, you need to increase the amount of CO2 to sustain it as well as nutrition and water. Temperature plays a definite role by regulating stomata opening but I have seen color without decreasing temps, and I think it has more to do with the cycle of the plants flowering. Once the plant goes into later flower, the need for light, water, nutrition and CO2 decreases which makes more of the need for temps to drop before doing damage.

 

[Aqua Man]

When you increase the intensity of light, you need to increase the amount of CO2 to sustain it as well as nutrition and water. Temperature plays a definite role by regulating stomata opening but I have seen color without decreasing temps, and I think it has more to do with the cycle of the plants flowering. Once the plant goes into later flower, the need for light, water, nutrition and CO2 decreases which makes more of the need for temps to drop before doing damage.

Yeah I get all that, I run a sealed CO2 supplemented room with full environmental control.

Found this article. Supports what you say but also UV is apparently important. Not a subject I'm very educated on but picking up stuff here and there.

Anthocyanin Biosynthesis and Degradation Mechanisms in Solanaceous Vegetables: A Review

Anthocyanins are a group of polyphenolic pigments that are ubiquitously found in the plant kingdom. In plants, anthocyanins play a role not only in reproduction, by attracting pollinators and seed dispersers, but also in protection against various abiotic and biotic stresses. There is...

www.frontiersin.org

 

[Smoking Gun]

Ok, just to take a step back and address the original issue, how to read the spectral analysis charts. The most important thing to remember is that white light contains ALL wavelengths of visible light. What is being shown in those graphs is how much of each wavelength is present in the light source. There are no equations or formulas to come to this conclusion, these are independent pieces of data that rely on no other factors and can be measured with the correct instrument. The curve of the cart is the intensity of each independent wavelength at the given distance from the light source. Ultimately you are just looking at how warm or cool your shade of white light is. In terms of standard incandescent bulbs it is warm white vs. soft white; warm white being in the 2,500 - 3,500 Kelvin range and cool white being in the 4,000 - 6,500 Kelvin range. What I find usually helps people is looking at the spectrum analysis of an HPS bulb versus a spectrum analysis of a LED unit. We all know that HPS throws out an orange light to our eyes, which means the light is deficient in blues predominantly, but still lacking in greens and reds too. There is a major peak in the 550-600nm wavelengths.

As was stated earlier the wavelengths we would want to see peaks in is 470nm (blue) and 660nm (far red) because those drive the major photosynthetic reactions within the plants. But as was discovered when the purple LED units were produced (using predominantly red and blue diodes) was that there was still something missing and the plants didn't grow as well. Once white diodes started to be placed into the units the production quality and quantity started to go back up; this is because the yellow, green and orange wavelengths are still utilized by the plants to run metabolic processes. Ultimately white light is always going to be the best option, just think about the sun which puts off true white light, that is the light that grows the best plants.

Yes if the intensity of the light is too weak the plants will not grow well, but if we get the right balance of spectrum and intensity we will grow plants to their greatest potential.

 

[Jahredi]

Ok, just to take a step back and address the original issue, how to read the spectral analysis charts. The most important thing to remember is that white light contains ALL wavelengths of visible light. What is being shown in those graphs is how much of each wavelength is present in the light source. There are no equations or formulas to come to this conclusion, these are independent pieces of data that rely on no other factors and can be measured with the correct instrument. The curve of the cart is the intensity of each independent wavelength at the given distance from the light source. Ultimately you are just looking at how warm or cool your shade of white light is. In terms of standard incandescent bulbs it is warm white vs. soft white; warm white being in the 2,500 - 3,500 Kelvin range and cool white being in the 4,000 - 6,500 Kelvin range. What I find usually helps people is looking at the spectrum analysis of an HPS bulb versus a spectrum analysis of a LED unit. We all know that HPS throws out an orange light to our eyes, which means the light is deficient in blues predominantly, but still lacking in greens and reds too. There is a major peak in the 550-600nm wavelengths.

As was stated earlier the wavelengths we would want to see peaks in is 470nm (blue) and 660nm (far red) because those drive the major photosynthetic reactions within the plants. But as was discovered when the purple LED units were produced (using predominantly red and blue diodes) was that there was still something missing and the plants didn't grow as well. Once white diodes started to be placed into the units the production quality and quantity started to go back up; this is because the yellow, green and orange wavelengths are still utilized by the plants to run metabolic processes. Ultimately white light is always going to be the best option, just think about the sun which puts off true white light, that is the light that grows the best plants.

Yes if the intensity of the light is too weak the plants will not grow well, but if we get the right balance of spectrum and intensity we will grow plants to their greatest potential.

Succinctly explained Smoking Gun. Thanks for addressing the original question.

And thanks to everyone else for the developing conversation. I’m finding this thread very educational and helpful

 

[Aqua Man]

Ok, just to take a step back and address the original issue, how to read the spectral analysis charts. The most important thing to remember is that white light contains ALL wavelengths of visible light. What is being shown in those graphs is how much of each wavelength is present in the light source. There are no equations or formulas to come to this conclusion, these are independent pieces of data that rely on no other factors and can be measured with the correct instrument. The curve of the cart is the intensity of each independent wavelength at the given distance from the light source. Ultimately you are just looking at how warm or cool your shade of white light is. In terms of standard incandescent bulbs it is warm white vs. soft white; warm white being in the 2,500 - 3,500 Kelvin range and cool white being in the 4,000 - 6,500 Kelvin range. What I find usually helps people is looking at the spectrum analysis of an HPS bulb versus a spectrum analysis of a LED unit. We all know that HPS throws out an orange light to our eyes, which means the light is deficient in blues predominantly, but still lacking in greens and reds too. There is a major peak in the 550-600nm wavelengths.

As was stated earlier the wavelengths we would want to see peaks in is 470nm (blue) and 660nm (far red) because those drive the major photosynthetic reactions within the plants. But as was discovered when the purple LED units were produced (using predominantly red and blue diodes) was that there was still something missing and the plants didn't grow as well. Once white diodes started to be placed into the units the production quality and quantity started to go back up; this is because the yellow, green and orange wavelengths are still utilized by the plants to run metabolic processes. Ultimately white light is always going to be the best option, just think about the sun which puts off true white light, that is the light that grows the best plants.

Yes if the intensity of the light is too weak the plants will not grow well, but if we get the right balance of spectrum and intensity we will grow plants to their greatest potential.

Great explanation. I'm a simpleton when it comes to lighting. Read a shit ton and some of it stuck but you managed to put it in a very clear concise manner that's easily understood.

 

[Smoking Gun]

Succinctly explained Smoking Gun. Thanks for addressing the original question.

And thanks to everyone else for the developing conversation. I’m finding this thread very educational and helpful

Of course, it hadn't been done so someone needed to step up and do it.

Great explanation. I'm a simpleton when it comes to lighting. Read a shit ton and some of it stuck but you managed to put it in a very clear concise manner that's easily understood.

I have far too much experience with lighting. I have a BFA in technical theater, I used to build sets; part of the degree was learning the physics of light. I now spend most of my day explaining this exact thing. When a simple base of knowledge can be laid it is much easier to understand more complex issues. I am more than happy to share the bit of info I do know. If there are other issues you are having feel free to let me know, I will try my best to offer an easy explanation.

 

[MIMedGrower]

Ok, just to take a step back and address the original issue, how to read the spectral analysis charts. The most important thing to remember is that white light contains ALL wavelengths of visible light. What is being shown in those graphs is how much of each wavelength is present in the light source. There are no equations or formulas to come to this conclusion, these are independent pieces of data that rely on no other factors and can be measured with the correct instrument. The curve of the cart is the intensity of each independent wavelength at the given distance from the light source. Ultimately you are just looking at how warm or cool your shade of white light is. In terms of standard incandescent bulbs it is warm white vs. soft white; warm white being in the 2,500 - 3,500 Kelvin range and cool white being in the 4,000 - 6,500 Kelvin range. What I find usually helps people is looking at the spectrum analysis of an HPS bulb versus a spectrum analysis of a LED unit. We all know that HPS throws out an orange light to our eyes, which means the light is deficient in blues predominantly, but still lacking in greens and reds too. There is a major peak in the 550-600nm wavelengths.

As was stated earlier the wavelengths we would want to see peaks in is 470nm (blue) and 660nm (far red) because those drive the major photosynthetic reactions within the plants. But as was discovered when the purple LED units were produced (using predominantly red and blue diodes) was that there was still something missing and the plants didn't grow as well. Once white diodes started to be placed into the units the production quality and quantity started to go back up; this is because the yellow, green and orange wavelengths are still utilized by the plants to run metabolic processes. Ultimately white light is always going to be the best option, just think about the sun which puts off true white light, that is the light that grows the best plants.

Yes if the intensity of the light is too weak the plants will not grow well, but if we get the right balance of spectrum and intensity we will grow plants to their greatest potential.

Just to correct and add something here. There are no “white” led diodes. They are blue coated with phosphers. And the universities are testing discreet colored diodes now. The agriculture lamps of the future will not be mostly “white” diodes. They will be actually more blurple. It has started already with the inclusion of red diodes and uva. The red is needed as the “white” diodes are really blue.

Also spectral charts are useful but do not show the intensity of the lamp. Wattage still determines yield. Intensity still beats spectrum. And quality is still mostly determined by intensity too. Spectrum can add quality but it is still mostly intensity.

The best and only clear advantage is the efficiency available to a quality led. But even if the led is twice as efficient as hps. It still wont grow twice the bud. Intensity is still more important.

 

[Aqua Man]

Just to correct and add something here. There are no “white” led diodes. They are blue coated with phosphers. And the universities are testing discreet colored diodes now. The agriculture lamps of the future will not be mostly “white” diodes. They will be actually more blurple. It has started already with the inclusion of red diodes and uva. The red is needed as the “white” diodes are really blue.

Also spectral charts are useful but do not show the intensity of the lamp. Wattage still determines yield. Intensity still beats spectrum. And quality is still mostly determined by intensity too. Spectrum can add quality but it is still mostly intensity.

The best and only clear advantage is the efficiency available to a quality led. But even if the led is twice as efficient as hps. It still wont grow twice the bud. Intensity is still more important.

That was this simpletons understanding also. The diode stuff I'm still learning but feel a balance is important as is with most things (what that balance is idk but Im sure it's not just red and blue). Intensity trumps all and spectrum becomes more important at the point of light saturation but also plant response to spectrum.

Good discussion and picking out some great points here.

@MIMedGrower but iin reference to not getting double the yeild would you agree theoretically eventually it's possible that LED provides the same yield with half the power requirements of HPS?

 

[MIMedGrower]

That was this simpletons understanding also. The diode stuff I'm still learning but feel a balance is important as is with most things (what that balance is idk but Im sure it's not just red and blue). Intensity trumps all and spectrum becomes more important at the point of light saturation but also plant response to spectrum.

Good discussion and picking out some great points here.

@MIMedGrower but iin reference to not getting double the yeild would you agree theoretically eventually it's possible that LED provides the same yield with half the power requirements of HPS?

Yes. And higher quality and even programmable control of plant growth depending on light colors and intensity.

 

[Smoking Gun]

Just to correct and add something here. There are no “white” led diodes. They are blue coated with phosphers. And the universities are testing discreet colored diodes now. The agriculture lamps of the future will not be mostly “white” diodes. They will be actually more blurple. It has started already with the inclusion of red diodes and uva. The red is needed as the “white” diodes are really blue.

Also spectral charts are useful but do not show the intensity of the lamp. Wattage still determines yield. Intensity still beats spectrum. And quality is still mostly determined by intensity too. Spectrum can add quality but it is still mostly intensity.

The best and only clear advantage is the efficiency available to a quality led. But even if the led is twice as efficient as hps. It still wont grow twice the bud. Intensity is still more important.

There is some change in the curve of the chart when the meter is moved further or closer to the light source, so some of that chart is based on intensity. At least there is some adjustment with the unit I have used to measure.

I cannot speak to the future LED units going back towards blurple, but I have heard a bit about discreet colored diodes and that is some interesting info. As you said the red diodes are added to counteract the levels of blue, but then there is no real need to include more blue diodes in my opinion.

I would still personally rather grow with LED these days. The light from HID lighting carries more heat and actually does more damage to the trichomes. And given that many people are replacing 1000 watt HPS units with 600-700 watts of LED it does seem the efficiency does equal a yield increase. If the same yield can be grown with 300 watts less of lighting it would seem to me that 1000 watts of LED would yield more than 1000 watts of HPS and still offer a greater quality.

But again, that is not what this thread was originally about. And in my honest opinion if you as a grower are more comfortable with growing under HPS then that is probably how you will achieve your best yields.

 

[MIMedGrower]

There is some change in the curve of the chart when the meter is moved further or closer to the light source, so some of that chart is based on intensity. At least there is some adjustment with the unit I have used to measure.

I cannot speak to the future LED units going back towards blurple, but I have heard a bit about discreet colored diodes and that is some interesting info. As you said the red diodes are added to counteract the levels of blue, but then there is no real need to include more blue diodes in my opinion.

I would still personally rather grow with LED these days. The light from HID lighting carries more heat and actually does more damage to the trichomes. And given that many people are replacing 1000 watt HPS units with 600-700 watts of LED it does seem the efficiency does equal a yield increase. If the same yield can be grown with 300 watts less of lighting it would seem to me that 1000 watts of LED would yield more than 1000 watts of HPS and still offer a greater quality.

But again, that is not what this thread was originally about. And in my honest opinion if you as a grower are more comfortable with growing under HPS then that is probably how you will achieve your best yields.

The quality can be kept up with hps simply by moving the plants away from the light a couple inches during ripening.

I will buy led when i think the tech has stabilized and the prices come way down. Lights are just tools. I dont have emotional attachment to them. For now hid stuff is even cheaper in price than before due to popularity and marketing hype of led.

And the diodes they are testing are not just red and blue. They are all the colors of the spectrum.

 

[Smoking Gun]

I will buy led when i think the tech has stabilized and the prices come way down. Lights are just tools. I dont have emotional attachment to them. For now hid stuff is even cheaper in price than before due to popularity and marketing hype of led.

I agree, that is why I built my own custom LED unit, cut the price in half. But there are actually good quality LED units hitting the market for reasonable prices these days, and the prices are only going to continue dropping. But hydro retailers are trying to give HID units away so they can stock the LED units.

 

[Aqua Man]

I still think with quality LED and HPS. There is very little difference in quality and yield. Most comes down to experience and other elemental factors.

I have a second grow going at another location for reasons with HPS I would have no problem recommending either.

I will admit though when the LED bashing starts from the HID guys I tend to kinda loose my shit. It's the one pet peeve I have that gets me going lol....

 

[MIMedGrower]

I still think with quality LED and HPS. There is very little difference in quality and yield. Most comes down to experience and other elemental factors.

I have a second grow going at another location for reasons with HPS I would have no problem recommending either.

I will admit though when the LED bashing starts from the HID guys I tend to kinda loose my shit. It's the one pet peeve I have that gets me going lol....

I dont get involved in the bashing and which is better arguments but i have to say on this and every other weed site the led guys are doing most of the bashing. And with a bunch of exagerated marketing hype.

They have no choice but to boldly defend their extremely overpriced purchase. And the same growers keep upgrading to newer led’s.

Why would they want to do that?

 

[Smoking Gun]

I still think with quality LED and HPS. There is very little difference in quality and yield. Most comes down to experience and other elemental factors.

I have a second grow going at another location for reasons with HPS I would have no problem recommending either.

I will admit though when the LED bashing starts from the HID guys I tend to kinda loose my shit. It's the one pet peeve I have that gets me going lol....

I don't like bashing of most of the products on the market; if they are working for someone they are worth having around. There are lots of things I may not be a fan of but my solution is to simply not use what I don't like. I am always of the opinion that I never try to fix what isn't broken. Improvement is good but that doesn't mean the previous method was ineffective.

 

[Smoking Gun]

They have no choice but to boldly defend their extremely overpriced purchase. And the same growers keep upgrading to newer led’s.

Why would they want to do that?

For the same reason HID growers changed from single ended bulbs to double ended bulbs, its a better product.

 

[MIMedGrower]

For the same reason HID growers changed from single ended bulbs to double ended bulbs, its a better product.

Its a different tool. Its only better if they are right for our space. In my case i would need at least 2 foot higher ceilings just to use one.

And the drawback with led for the same reason is i need the heat from my hps lamps in winter. I might need a heater during lights on with a super efficient led lamp. And that would negate the benefits.

Right tool for the job is all i ever want.

 

[Smoking Gun]

Its a different tool. Its only better if they are right for our space. In my case i would need at least 2 foot higher ceilings just to use one.

And the drawback with led for the same reason is i need the heat from my hps lamps in winter. I might need a heater during lights on with a super efficient led lamp. And that would negate the benefits.

Right tool for the job is all i ever want.

Very true. A drill is a great tool, but not when you are trying to drive a nail.

 

[Aqua Man]

[QUOTE="MIMedGrower, post: 2305618, member: 81605]
Right tool for the job is all i ever want.
[/QUOTE]

This I can't even explain how right this is.

 

[MIMedGrower]

[QUOTE="MIMedGrower, post: 2305618, member: 81605]
Right tool for the job is all i ever want.

This I can't even explain how right this is.
[/QUOTE]


Now if only the practically religious arguers of defoliation, flushing and additives could keep it in their tool box. ;-)