LM301H vs LM301H-EVO

[RainDan]

Hi RIU,

New research is emerging that is showing that the old tried and true 3500K + 660nM is still the go to for full cycle/flowering.

The irony is, many innovators in the LED space started their R&D right here (ourselves included back in the Timber days) about a decade ago when CXB3590 COBs were all the rage. Many have gone on to continue our work in the industry in varying capacities. And many of those espoused the benefits of using 3500K + 660 nM so much so that they even built entire companies around the concept.

When LM301H-EVO and mint white started being talked about we looked but were skeptical. The information flew in the face of years of research on different spectrum usages in growing cannabis, and it always came back to deep red, specifically in the 630-660 nM range for flowering.

To make up for a lack of 3500K in the color temperature options, many manufacturers have gone to a 3000K/5000K mix with additional discrete spectra like 660 nM, 730 nM and even UV added to more approximate the McCree spectrum, the ideal benchmark for cannabis and other flowering/fruiting plants.

We are moving to a 3500K + 660 nM model lineup for a few reasons mentioned above. But mainly because while it might not be as "efficient", we believe based on feedback from growers we trust that have tested various color temperatures, that 3500K + 660 nM performs the best on cannabis.

What are your thoughts? We would love to hear your feedback.

 

[KitnerPush]

Well, first the EVO diode is more efficient. It also brings benefits in terms of higher flavinols compared to the 310b/h. Also, I think some of the independent UV and near UV research done here alludes to the fact that a 437nm pump vs. a 450nm pump is going to get you higher cannabinoids.

In terms of price/w 3500k 301H/B and 660's will suffice, but if it is any better? Well I'd have to see the actual lab reports that back it up.

 

[Rocket Soul]

Well, first the EVO diode is more efficient. It also brings benefits in terms of higher flavinols compared to the 310b/h. Also, I think some of the independent UV and near UV research done here alludes to the fact that a 437nm pump vs. a 450nm pump is going to get you higher cannabinoids.

In terms of price/w 3500k 301H/B and 660's will suffice, but if it is any better? Well I'd have to see the actual lab reports that back it up.

The evo diode is more efficient vut mainly cause its ccts arent really comparable directly to a 450nm pohoton pumps ccts. Since you move the blue pump to 437, which is less bright to the human eye, the diode uses less phosphor to get to the same cct. Check the spectrums in the datasheets side by side, youll see one salient thing: the blue spike is allways taller in the evo, meaning less phosphor and more light. But its like you would be comparing a 3000k diode to a 4000k diode. The efficiency boost is in this, a more blue heavy spectrum.

Ive not seen the uv/flavonoid/thc research re this diode, could you link it please?

 

[Prawn Connery]

Hi RIU,

New research is emerging that is showing that the old tried and true 3500K + 660nM is still the go to for full cycle/flowering.

The irony is, many innovators in the LED space started their R&D right here (ourselves included back in the Timber days) about a decade ago when CXB3590 COBs were all the rage. Many have gone on to continue our work in the industry in varying capacities. And many of those espoused the benefits of using 3500K + 660 nM so much so that they even built entire companies around the concept.

When LM301H-EVO and mint white started being talked about we looked but were skeptical. The information flew in the face of years of research on different spectrum usages in growing cannabis, and it always came back to deep red, specifically in the 630-660 nM range for flowering.

To make up for a lack of 3500K in the color temperature options, many manufacturers have gone to a 3000K/5000K mix with additional discrete spectra like 660 nM, 730 nM and even UV added to more approximate the McCree spectrum, the ideal benchmark for cannabis and other flowering/fruiting plants.

We are moving to a 3500K + 660 nM model lineup for a few reasons mentioned above. But mainly because while it might not be as "efficient", we believe based on feedback from growers we trust that have tested various color temperatures, that 3500K + 660 nM performs the best on cannabis.

What are your thoughts? We would love to hear your feedback.

It depends on what you mean by "performs best on cannabis"

We have always seen a trade-off between the blue and red ends of the spectrum in terms of yield vs quality (cannabinoid content). This goes back to the days of MH vs HPS vs CMH.

It is very easy to make an efficient light using only 3500K phosphor whites and 660nm monos. However, the benefits of far red are also proven, so I would never think to design another grow light without it. Even if it hurts efficiency.

Same goes for UVA. There is perhaps a bigger debate about the merits of UVA vs none, but the research is a bit sparse and it all depends on who's results you believe.

The same goes for plant absorption spectra. I don't know if I agree with the statement that the McCree Curve is the "benchmark for cannabis" as it was formulated under specific conditions using specific crops that didn't even include cannabis!

As for the absorption spectra themselves, these also change depending on the solvent used to measure. Some argue that chlorophyll is much bluer in situ than it is under lab conditions (which use ethanol and other solvents).



Looking at this graph, we're all missing a trick with the typical blue-pump cyan gap of white phosphors in relation to Chl B, whilst the Chl A blue peak appears to be closer to 420nm than 450 or even 437nm.

But this is just one graph of many. Below, same graph, different conditions, different spectral peaks. Who do you believe?



We also know that chloroplasts have a high degree of plasticity and can change their ratios depending on the available light. So perhaps there is no "one size fits all" spectrum. Most LED grow lights are very different to sunlight – which I would argue is closer to the "benchmark for cannabis" . . . but then which sunlight do we use, as sunlight is also dynamic?

Sunlight (on average) has 25% far red and 5% UV – when was the last time you saw that in an indoor growlight?

Sorry for the long post, but if it were me, I would combine both 437nm and 450nm pumps to get a broader blue spectrum . . but I would also be trying to get back some cyan, have a lot more far red and fill out the violet/UVA end of the curve which have known photomorphogenic qualities.

 

[RainDan]

Well, first the EVO diode is more efficient. It also brings benefits in terms of higher flavinols compared to the 310b/h. Also, I think some of the independent UV and near UV research done here alludes to the fact that a 437nm pump vs. a 450nm pump is going to get you higher cannabinoids.

In terms of price/w 3500k 301H/B and 660's will suffice, but if it is any better? Well I'd have to see the actual lab reports that back it up.

Thank you for the contribution I appreciate it. That the EVO is more efficient there is no argument. This is due mainly to the enhanced blue spectral output and relative lack therefore of red as a compensatory point on which we can all agree.

If you could point us to the flavonoid and cannabinoid data I would appreciate it. These types of data points are critical to helping develop an understanding of the interaction of LED vs natural sunlights actions on cannabis plant development.

I really appreciate the feedback please feel free to share more.

 

[RainDan]

The evo diode is more efficient vut mainly cause its ccts arent really comparable directly to a 450nm pohoton pumps ccts. Since you move the blue pump to 437, which is less bright to the human eye, the diode uses less phosphor to get to the same cct. Check the spectrums in the datasheets side by side, youll see one salient thing: the blue spike is allways taller in the evo, meaning less phosphor and more light. But its like you would be comparing a 3000k diode to a 4000k diode. The efficiency boost is in this, a more blue heavy spectrum.

Ive not seen the uv/flavonoid/thc research re this diode, could you link it please?

Hi @Rocket Soul

Great to hear from you thanks for chiming in. I agree with all of your points and am also very interested in the effects of the higher frequency parts of the spectral curve, both pro and con. More light means more photon velocity or flux. This higher energy may or may not be beneficial to certain photoreceptors and biological processes during flowering. And if so is there a timing factor at play or are certain spectra more absorbable? There is a huge amount of testing to be done and cannabis testing naturally is far behind the curve due to legality.

Thanks again for the contribution I really appreciate it.

Take care
Dan

 

[KitnerPush]

The evo diode is more efficient vut mainly cause its ccts arent really comparable directly to a 450nm pohoton pumps ccts. Since you move the blue pump to 437, which is less bright to the human eye, the diode uses less phosphor to get to the same cct. Check the spectrums in the datasheets side by side, youll see one salient thing: the blue spike is allways taller in the evo, meaning less phosphor and more light. But its like you would be comparing a 3000k diode to a 4000k diode. The efficiency boost is in this, a more blue heavy spectrum.

Ive not seen the uv/flavonoid/thc research re this diode, could you link it please?

cant find it right now, but the testing is done by samsung themselves. And I'm also pretty sure that research points to the fact that plants do not really care that much about color temperature, as long as you have the correct wavelengths within the PE spectrum.

 

[RainDan]

It depends on what you mean by "performs best on cannabis"

We have always seen a trade-off between the blue and red ends of the spectrum in terms of yield vs quality (cannabinoid content). This goes back to the days of MH vs HPS vs CMH.

It is very easy to make an efficient light using only 3500K phosphor whites and 660nm monos. However, the benefits of far red are also proven, so I would never think to design another grow light without it. Even if it hurts efficiency.

Same goes for UVA. There is perhaps a bigger debate about the merits of UVA vs none, but the research is a bit sparse and it all depends on who's results you believe.

The same goes for plant absorption spectra. I don't know if I agree with the statement that the McCree Curve is the "benchmark for cannabis" as it was formulated under specific conditions using specific crops that didn't even include cannabis!

As for the absorption spectra themselves, these also change depending on the solvent used to measure. Some argue that chlorophyll is much bluer in situ than it is under lab conditions (which use ethanol and other solvents).

View attachment 5350757

Looking at this graph, we're all missing a trick with the typical blue-pump cyan gap of white phosphors in relation to Chl B, whilst the Chl A blue peak appears to be closer to 420nm than 450 or even 437nm.

But this is just one graph of many. Below, same graph, different conditions, different spectral peaks. Who do you believe?

View attachment 5350758

We also know that chloroplasts have a high degree of plasticity and can change their ratios depending on the available light. So perhaps there is no "one size fits all" spectrum. Most LED grow lights are very different to sunlight – which I would argue is closer to the "benchmark for cannabis" . . . but then which sunlight do we use, as sunlight is also dynamic?

Sunlight (on average) has 25% far red and 5% UV – when was the last time you saw that in an indoor growlight?

Sorry for the long post, but if it were me, I would combine both 437nm and 450nm pumps to get a broader blue spectrum . . but I would also be trying to get back some cyan, have a lot more far red and fill out the violet/UVA end of the curve which have known photomorphogenic qualities.

Hello @Prawn Connery

It is great to hear from you. I have enjoyed your posts and you are a great source of information regarding LEDs. I concur regarding your points on the subjectiveness of the use of words like “better” because growers may be trying to achieve differing results depending on their medicinal needs.

I like what you have to say about the use of UV and IR as well as deeper blues. My question - do you think it advantageous to add these diodes to a main board in lieu of broader white spectrum diodes due to the relative differences in both energy output as well as overall spectral enhancements? My thoughts are along the same lines however having them as true supplementary spectrum to be used only at certain points during the grow cycle. This gives the main light the benefit of having the higher PPF output without having to give up the inherent benefits proven in a 3500K + 660 set up.

in fairness, this is a more complicated route that I am describing however some growers may not find the need nor want for additional overhead in the garden. Alternatively/ spectrum hunters would most assuredly like the idea.

This could very well be another classic “Ford vs Chevy” discussion, however I do truly believe there is more to it than opinions.

Thank you once again for your valued contribution- I look forward to additional discussions.

Take care
Dan

 

[RainDan]

cant find it right now, but the testing is done by samsung themselves.

cant find it right now, but the testing is done by samsung themselves. And I'm also pretty sure that research points to the fact that plants do not really care that much about color temperature, as long as you have the correct wavelengths within the PE spectrum.

Samsung has done copious amounts of testing including flavonoid production on non cannabis devices plants - here is one such example:

https://image.led.samsung.com/content/samsung/p6/led/insights/insight-detail-20/Samsung_Horticulture_Technical_Brochure_190627.pdf

I am unaware of the Samsung Corporation doing any such test on Cannabis. If you have these results I would appreciate if you included them. Myself and others would be very grateful.

Thank you.

 

[KitnerPush]

Samsung has done copious amounts of testing including flavonoid production on non cannabis devices plants - here is one such example:

https://image.led.samsung.com/content/samsung/p6/led/insights/insight-detail-20/Samsung_Horticulture_Technical_Brochure_190627.pdf

I am unaware of the Samsung Corporation doing any such test on Cannabis. If you have these results I would appreciate if you included them. Myself and others would be very grateful.

Thank you.

If there is, I'm sure it's proprietary for the time being.

 

[Rocket Soul]

cant find it right now, but the testing is done by samsung themselves. And I'm also pretty sure that research points to the fact that plants do not really care that much about color temperature, as long as you have the correct wavelengths within the PE spectrum.

cant find it right now, but the testing is done by samsung themselves. And I'm also pretty sure that research points to the fact that plants do not really care that much about color temperature, as long as you have the correct wavelengths within the PE spectrum.

Indeed, all im pointing out is that comparing evo to standard, using the same cct, is not apples to apples: its like comparing a 4000k to a 3000k diode. Cct is human eye specific: since different blues give different impressions in our eyes a light can actually have more actual watts of blue but look the same color temp. This is a bit missleading, if you compare with equal amounts of blue in each chip the case for more efficiency is not as clear cut as one might think. If all we think about is efficiency then we would only use a blue diode without phosphor but then were back to blurple again.

As for the plant caring about color temp: again the previous discussion: plants care about radiant output (as in actual percentage of blue vrs redvrs greenvra far red) while color temps is a matter of human vision. You can get the same cct with 15% blue as you could with 20% blue, provided that the second example we use a blue which is less luminous; generates less reaponse in our eyes. The plant will care of these percentages, not the actual cct. As long as you use the same photon pump all of this is not important since the blue in our spectrum is allways the same. When you use a different blue with less luminosity (=eye response per watt) then all ccts will be off by a bit.

 

[RainDan]

Indeed, all im pointing out is that comparing evo to standard, using the same cct, is not apples to apples: its like comparing a 4000k to a 3000k diode. Cct is human eye specific: since different blues give different impressions in our eyes a light can actually have more actual watts of blue but look the same color temp. This is a bit missleading, if you compare with equal amounts of blue in each chip the case for more efficiency is not as clear cut as one might think. If all we think about is efficiency then we would only use a blue dipde without phosphor but then were back to blurple again.

This

 

[KitnerPush]

yeah but what kind of blue diode is the question here... a 435nm one or a 450nm one? There are many good arguments for using green light, and personally I'm more in favor of green light... the green light is what makes it white to our eye. I don't think using 2700k diodes is going to be better than using 5600k diodes and 660nm...

 

[KitnerPush]

also, if the point is to mimic HID lighting with LED, then just buy HID... it's cheaper. The whole idea with using LED is you can customize spectrum based on wavelengths of light and increase the efficiency per watt.

 

[Rocket Soul]

yeah but what kind of blue diode is the question here... a 435nm one or a 450nm one? There are many good arguments for using green light, and personally I'm more in favor of green light... the green light is what makes it white to our eye. I don't think using 2700k diodes is going to be better than using 5600k diodes and 660nm...

Weve run spectrum tests with all sorts of spectrums; the results are very varied, sometimes we get better from one then next from another. If intensity is similar theres very little difference between yields. Our latest favorite seems to be 2700k 90cri + ample 660 and then 400nm on a separate channel. The quality was just a lot better but with very similar yield against other spectrums were running. We were using about 10% power to our uv 400/365nm but using china diodes with unknown efficiency.

 

[RainDan]

yeah but what kind of blue diode is the question here... a 435nm one or a 450nm one? There are many good arguments for using green light, and personally I'm more in favor of green light... the green light is what makes it white to our eye. I don't think using 2700k diodes is going to be better than using 5600k diodes and 660nm...

I am not espousing the use of discreet blue diodes, rather the discussion is around the use of a white spectrum SMT diode that has certain wavelength

also, if the point is to mimic HID lighting with LED, then just buy HID... it's cheaper. The whole idea with using LED is you can customize spectrum based on wavelengths of light and increase the efficiency per watt.

I appreciate your positions however there has been a ton of testing pointing to the benefits of LED over HID

also, if the point is to mimic HID lighting with LED, then just buy HID... it's cheaper. The whole idea with using LED is you can customize spectrum based on wavelengths of light and increase the efficiency per watt.

The point is not to reproduce HID but rather to improve upon it. Customizing spectrum is only one of many attributes LEDs have that HID never will.

While HID is cheaper from a CAPEX standpoint your TOTEX costs are not as there is a break even point , speaking solely regarding costs.

 

[KitnerPush]

Weve run spectrum tests with all sorts of spectrums; the results are very varied, sometimes we get better from one then next from another. If intensity is similar theres very little difference between yields. Our latest favorite seems to be 2700k 90cri + ample 660 and then 400nm on a separate channel. The quality was just a lot better but with very similar yield against other spectrums were running. We were using about 10% power to our uv 400nm but using china diodes with unknown efficiency.

Yes, white in combination with red will always be favorable no matter what ct. Intensity is a more interesting subject, efficiency aside. You could reach the same system color temperature using straight 5000K whites and compensate with red, and be considerably more efficient and increase intensity.

 

[Prawn Connery]

yeah but what kind of blue diode is the question here... a 435nm one or a 450nm one? There are many good arguments for using green light, and personally I'm more in favor of green light... the green light is what makes it white to our eye. I don't think using 2700k diodes is going to be better than using 5600k diodes and 660nm...

2700K CRI90 is one of my favourite LEDs, because it has a good amount of far red light and does not have a huge cyan gap in the blue zone. And if you buy the right ones, they can also be very efficient in terms of radiant energy.

Green is interesting because not that long ago everyone was running around saying plants don't use green because they reflect most of it.

We now know much better: green is arguably the most efficient spectrum because it activates chloroplasts deep in the leaf tissue and is less likley to cause photo-oxidative stress. If you think about it in evolutionary terms, why wouldn't plants use the most abundant (and efficient) spectra to redistribute light to the lower canopy? And so green light is reflected deeper into the canopy and can help with penetration.

However, green still has a lower quantum yield than red and appears to have a similar photomorphogenic response, so it has its place in a balanced spectrum but red is still king IMO.

Perhaps the biggest point to take away from all this is that there is still so much we don't know and won't know until we start doing more serious tesing in relation to medicinal cannabis (and other species). Sometimes our understanding takes a complete U-turn – as is the case for green light – whilst in othe respects it takes a long time for common views to catch up to what some people intrinsically already know.

Bruce Bugbee, for example, has only recently started touting the effects of far red light. It just happens to coincide with his company, Apogee, bringing out an "ePAR" meter that measures far red. Go back through his earlier videos, and he doesn't lend as much weight to far red – indeed, he lists only the negative aspects, such as potential shade avoidance (which can be offset by adding UV).

However, there were growers out there who had been playing with far red light for much longer - and more importantly, in the context of growing cannabis – so IMO they were far ahead of the curve. So far ahead that others are only now catching up.

 

[KitnerPush]

I would argue that the overall plant health would be better also.

 

[KitnerPush]

2700K CRI90 is one of my favourite LEDs, because it has a good amount of far red light and does not have a huge cyan gap in the blue zone. And if you buy the right ones, they can also be very efficient in terms of radiant energy.

Green is interesting because not that long ago everyone was running around saying plants don't use green because they reflect most of it.

We now know much better: green is arguably the most efficient spectrum because it activates chloroplasts deep in the leaf tissue and is less likley to cause photo-oxidative stress. If you think about it in evolutionary terms, why wouldn't plants use the most abundant (and efficient) spectra to redistribute light to the lower canopy? And so green light is reflected deeper into the canopy and can help with penetration.

However, green still has a lower quantum yield than red and appears to have a similar photomorphogenic response, so it has its place in a balanced spectrum but red is still king IMO.

Perhaps the biggest point to take away from all this is that there is still so much we don't know and won't know until we start doing more serious tesing in relation to medicinal cannabis (and other species). Sometimes our understanding takes a complete U-turn – as is the case for green light – whilst in othe respects it takes a long time for common views to catch up to what some people intrinsically already know.

Bruce Bugbee, for example, has only recently started touting the effects of far red light. It just happens to coincide with his company, Apogee, bringing out an "ePAR" meter that measures far red. Go back through his earlier videos, and he doesn't lend as much weight to far red – indeed, he lists only the negative aspects, such as potential shade avoidance (which can be offset by adding UV).

However, there were growers out there who had been playing with far red light for much longer - and more importantly, in the context of growing cannabis – so IMO they were far ahead of the curve. So far ahead that others are only now catching up.

Yes, his colleague used laser diodes for the testing as laser diodes have a very narrow spectrum. I think luminus' diodes have a 5nm variance so its hard to pinpoint exact data without laser diodes... which btw have not been developed yet. I think, however, that far red in terms of application is probably more suited for leafy greens, although there may be a case, especially, for 'light-treatment' intervals both for UV and FR in cannabis. FR especially in late stretch/early flower... the big question is which specific wavelength? or combination of wavelenghts? will yield bigger buddage.