LM301H vs LM301H-EVO
- Thread starter RainDan
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I doubt AI is the tool for the job. It's garbage in, garbage out.
At the moment there is not sufficient data to say how to design/use and optimal light (and high quality data is even sparser).
And when you think about how to use multi channel light what do you want to do with it? Different ratios of UV/RGB/IR (at how many levels?), different spectra at different stages of the light cycles (more blue during veg)? Different spectra throughout the day (e.g. end of day IR treatment or mimick the high UVB during noon of the sun)? And then you can imagine many other combinations (at different levels too!) that does not follow the blueprint of the sun. When you count count it all up and include replicates you are looking at tens of thousands of data points that need to be collected to answer the question. With AI being 'data inefficient', as in needing a lot of data to even produce meaningless results the effort is prohibitive.
What was used in the agriculture industry and research in the past for similiar problems is statistical analysis and design of experiment. Optimizing fertilizer is an equaly complex task. With there being 17 elements, different forms of each element, a life cycle and influences of soil.
DoE makes it possible to reduce the number of experiments needed and still draw meaninful conclusions. And the best part is you can analyze the process and don't rely on a black box AI gizmo.
A general note: I doubt sunlight is the best spectrum. Sure it is what plants are adapted to put up with but if you move to artificial environments there is surely something better. If in nature 50 % of a population dies every winter and replenishes itself in summer that's a successful strategy. But would you build a business where half of your produced good goes to recycling? Would customers pay for that?
Rocket Soul
Well-Known Member
AI: i think it would be hard to get an AI guided spectrum control to work right. Its a matter of datapoints; in order to train your ai you need data. The relevant data with regards to spectrum would likely be yield and quality (but i guess you could add more if creative) Both those datapoints are scarce: you only get a yield number once every 2 months and quality numbers, as measured by cannabinodes, are expensive and unlikely to be made more than once or twice a crop. With this little data how is the ai supposed to learn?
you could maybe get ai to control your environment targeting a specific vpd (rather than targeting temps/rh of desired vpd), that should be easier to manage with sensors, extraction/AC/Dehuey control. If using lung rooms/having to open and close doors and windows: you can even setup automatic window/door openers nowadays.
you could maybe get ai to control your environment targeting a specific vpd (rather than targeting temps/rh of desired vpd), that should be easier to manage with sensors, extraction/AC/Dehuey control. If using lung rooms/having to open and close doors and windows: you can even setup automatic window/door openers nowadays.
For that PID (proportional-integral-derivative) controllers are used. They look at the actual value, the set value and the rate of change in the relevant past time frame. Using that large differences between actual value and set point are corrected quickly and slower the closer both values are.
KitnerPush
Active Member
I don't want to get to specific, but any accurate data in the development of a plant in relation to spectrum is extreemely valuable.
Charles U Farley
Well-Known Member
If you're going to post info that's AI derived, some of us would appreciate knowing what AI you used and what prompts you use to get the info.
Just a thought.
KitnerPush
Active Member
It's not related to this thread.
Prawn Connery
Well-Known Member
Here's why I believe the secret is red and far red. Nichia did a lot of testing of their Hortisolis range and published their results. The Hortisolis LED is in red and includes a broad-based deep/far red phosphor.
Admittedly, the black line is a typical 5000K CRI80 diode which would not be my first choice for growing – so if they are comparing Hortisolis with 5000K CRI80 then you would expect the redder light to have much better results.
But the interesting thing is, these diodes are not very efficient – due to the deep/far red phosphor – yet still produced great results with around 10% less PPFD.
Flowering plants
Lettuce
Here's the report: https://led-ld.nichia.co.jp/en/product/lighting_hortisolis.html
Admittedly, the black line is a typical 5000K CRI80 diode which would not be my first choice for growing – so if they are comparing Hortisolis with 5000K CRI80 then you would expect the redder light to have much better results.
But the interesting thing is, these diodes are not very efficient – due to the deep/far red phosphor – yet still produced great results with around 10% less PPFD.
Flowering plants
Lettuce
Here's the report: https://led-ld.nichia.co.jp/en/product/lighting_hortisolis.html
KitnerPush
Active Member
That's interesting. They don't mention much about the conventional LED they are using. Lookis like a 5000k or 6500k as dude to lack of green. Added far red in the spectrum will improve growth, but you can get better concentrations in using DR and FR diodes.
RainDan
Well-Known Member
If you don't mind me asking you, solely as a grower, what kinds of new combinations are you considering? And what is your motivation?
Thank you in advance - I think that the technical points raised thus far are super valuable. Equally valuable, is what the grower is looking for and why.
sfw1960
Well-Known Member
I've been running HLG QB288"s & QB132's for the majority in 3000k (mostly) and a few 4000k but I'm adding some HLG QB272 Rspec FR for the 660/730nm.
I have no problem getting large enough yields and I also believe (as kinda shown here in the posts) you are going to get only so much biomass from a seed and the THC content is "watered down" after you get so much mass and the net potency is the same or similar on a smaller plant - I've grown a few bigger ones and that seems to be the case from my limited experience.
Running up less time and energy for a decent yield increase is something worth looking into.
If that makes sense...
RainDan
Well-Known Member
Makes perfect sense, thank you so much for sharing. And good choice in equipment - HLG makes good products and Steven and Amit (the principals) are both really good people.
Have you considered running 660/730 nM boards as a separate item with separate controllability, or do you prefer the QB 272 because it also adds more PPF from the white diodes, or......?
Thank you again for sharing your thoughts.
sfw1960
Well-Known Member
The DIY boards are very inexpensive and are an exact drop in for the other older QBs - that and anything I've used from Stephen and Amit has been a great product.
I've looked at adding the reds using strip LEDs or 20 mm Star MCPCB's and aluminum angle or tubing, but for cost it's a little bit less money to get the HLG boards and use both (like I'm planning on) rather than get the supplemental add ons because nobody is giving them away and I'm a cheapskate.
I'd rather have more lighting than needed running softer than have to whip on the optoelectronics for every drop of PPFD you can squeeze out of them and uniformity has always been a challenge.
cdgmoney250
Well-Known Member
I’m not sure what secret you’re referring to, but I believe the proportions of Blue to Red photons as well as covering the red end of chlorophyll a, are why the plants in that study you cited did better under the Hortisolis chips vs the 5000k 80CRI chips. Not just the additional red nanometers.
The red end of the spectrum on the 80CRI chips hardly even covers Chlorophyll a absorption, and the peak of about 615nm on the red end was about 50% relative output compared to the blue peak at 450nm.
Compared to the Nichia Hortisolis chip, where blue peak and red peak are almost even with each other regarding relative output, similar to chlorophyll absorption charts. I’ve taken the liberty to draw on the spectrum graph to illustrate what I’m talking about.
The yellow line is the Hortisolis and the green line is the 80CRI 5000k
Now notice the similar absorption from Blue Peak to Red Peak of Chlorophyll a (black line).
Now notice below the correlation between the chlorophyll a & b absorption vs the action and how they almost follow each
This in combination with the photosynthetic effects of green/yellow/orange wavelengths is what I believe the “secret” to be. Which is really no secret at all, it’s just getting a spectrum that is broader/balanced and closer to natural sunlight. Weird right?
I don’t think the addition of certain wavelengths alone will have an outstanding impact on photosynthesis if the spectrum is not balanced properly. Especially when the additional wavelengths come from monochromatic diodes. Research seems to agree with this view.
Photosynthetic Physiology of Blue, Green, and Red Light: Light Intensity Effects and Underlying Mechanisms - PMC
Red and blue light are traditionally believed to have a higher quantum yield of CO2 assimilation (QY, moles of CO2 assimilated per mole of photons) than green light, because green light is absorbed less efficiently. However, because of its lower ...
www.ncbi.nlm.nih.gov
This, IMO, is why red heavy spectrums often aren’t the “best” for growing, or at least don’t offer the growth benefits that many claim. Imbalance.
This is a great study from 2022 about testing different wavelengths/combinations of light at varying flux levels.
“Modulations in Chlorophyll a Fluorescence Based on Intensity & Spectral Variations in Light”
Modulations in Chlorophyll a Fluorescence Based on Intensity and Spectral Variations of Light - PMC
Photosynthetic efficiency is significantly affected by both qualitative and quantitative changes during light exposure. The properties of light have a profound effect on electron transport and energy absorption in photochemical reactions. In ...
www.ncbi.nlm.nih.gov
RainDan
Well-Known Member
I concur - I think most would agree that is the smart approach.
Prawn Connery
Well-Known Member
You will note that I did mention this at the time of posting:I’m not sure what secret you’re referring to, but I believe the proportions of Blue to Red photons as well as covering the red end of chlorophyll a, are why the plants in that study you cited did better under the Hortisolis chips vs the 5000k 80CRI chips. Not just the additional red nanometers.
The red end of the spectrum on the 80CRI chips hardly even covers Chlorophyll a absorption, and the peak of about 615nm on the red end was about 50% relative output compared to the blue peak at 450nm.
Compared to the Nichia Hortisolis chip, where blue peak and red peak are almost even with each other regarding relative output, similar to chlorophyll absorption charts. I’ve taken the liberty to draw on the spectrum graph to illustrate what I’m talking about.
View attachment 5351540
The yellow line is the Hortisolis and the green line is the 80CRI 5000k
View attachment 5351541
Now notice the similar absorption from Blue Peak to Red Peak of Chlorophyll a (black line).
View attachment 5351542
Now notice below the correlation between the chlorophyll a & b absorption vs the action and how they almost follow each
View attachment 5351543
This in combination with the photosynthetic effects of green/yellow/orange wavelengths is what I believe the “secret” to be. Which is really no secret at all, it’s just getting a spectrum that is broader/balanced and closer to natural sunlight. Weird right?
I don’t think the addition of certain wavelengths alone will have an outstanding impact on photosynthesis if the spectrum is not balanced properly. Especially when the additional wavelengths come from monochromatic diodes. Research seems to agree with this view.
Photosynthetic Physiology of Blue, Green, and Red Light: Light Intensity Effects and Underlying Mechanisms - PMC
Red and blue light are traditionally believed to have a higher quantum yield of CO2 assimilation (QY, moles of CO2 assimilated per mole of photons) than green light, because green light is absorbed less efficiently. However, because of its lower ...
This, IMO, is why red heavy spectrums often aren’t the “best” for growing, or at least don’t offer the growth benefits that many claim. Imbalance.
This is a great study from 2022 about testing different wavelengths/combinations of light at varying flux levels.
“Modulations in Chlorophyll a Fluorescence Based on Intensity & Spectral Variations in Light”
Modulations in Chlorophyll a Fluorescence Based on Intensity and Spectral Variations of Light - PMC
Photosynthetic efficiency is significantly affected by both qualitative and quantitative changes during light exposure. The properties of light have a profound effect on electron transport and energy absorption in photochemical reactions. In ...
What I should have mentioned is that both those diodes are 5000K. Actually, the Hortisolis is 5300K. That, in itself, doesn't mean much because there are lots of ways of getting the same CCT with very different spectra.Prawn Connery said:
There is also a large difference in the amount of red distribution, which is not ideal – as I noted.
But I'm also not as interested in the absorption spectra as I am in the action spectra. Again, I've already mentioned that there are lots of absorprtion graphs out there and they change depending on the methodologies used to measure them.
So lets look at the McCree curve. Not ideal, but let's look at it anyway.
Green light does not lose out as much to red light as you might think. It has the added benefit of better penetration. It is still not as active as red, but generally speaking you can replace red with green with very little change in photomorphogenic response and similar yields.
This is where far red light comes into its own. Far Red has a synergistic relationship with red light. Far Red quenches (cools) red pigments which allows them to absorb and photosynthesise about 10% more of the sum of each red + far red photon. It's called the Emerson Effect, which I'm sure you've herard of.
However, far red also drives photomorphogenic response changes which make leaves bigger and internodes longer. This in turn increases the surface area of the leaf (as well as penetration due to longer internode spacing) which is essentially a bigger solar panel.
Hortisolis has more red than 5000K CRI80 which has more green than Hortisolis. But you also need to realise that these types of spectral graphs are relative to "area under the curve". The 5000K CRI80 has less area under the curve, so each spectral peak has a higher absolute value than the Hortisolis.
When you take this into account, both diodes have similar amounts of green and red combined. Not the same, but not as diverse as you might think.
Let's not forget that Nichia has access to almost any diode it wants, including those with much higher red levels but lower far red levels.
Their testing could have included for example 5000K CRI90:
Or even better, 3000K CRI90:
But their in-house testing led to the development of a white-phosphor diode with elevated levels of far red.
Now, you can take what I say with a pinch of salt. But Nichia is the world's biggest LED company and has a stable of scientists working on stuff like this and the spectrum they came up with had eleveated levels of far red.
Why?
Rocket Soul
Well-Known Member
Although i do find this quite interesting its a bit hard to understand what you're arguing here. Seems to be that you should judge a spectrum on its highest peaks of red/blue rather than total amount of blue light vrs red light, is that right? Please correct me if i misunderstood.I’m not sure what secret you’re referring to, but I believe the proportions of Blue to Red photons as well as covering the red end of chlorophyll a, are why the plants in that study you cited did better under the Hortisolis chips vs the 5000k 80CRI chips. Not just the additional red nanometers.
The red end of the spectrum on the 80CRI chips hardly even covers Chlorophyll a absorption, and the peak of about 615nm on the red end was about 50% relative output compared to the blue peak at 450nm.
Compared to the Nichia Hortisolis chip, where blue peak and red peak are almost even with each other regarding relative output, similar to chlorophyll absorption charts. I’ve taken the liberty to draw on the spectrum graph to illustrate what I’m talking about.
View attachment 5351540
The yellow line is the Hortisolis and the green line is the 80CRI 5000k
View attachment 5351541
Now notice the similar absorption from Blue Peak to Red Peak of Chlorophyll a (black line).
View attachment 5351542
Now notice below the correlation between the chlorophyll a & b absorption vs the action and how they almost follow each
View attachment 5351543
This in combination with the photosynthetic effects of green/yellow/orange wavelengths is what I believe the “secret” to be. Which is really no secret at all, it’s just getting a spectrum that is broader/balanced and closer to natural sunlight. Weird right?
I don’t think the addition of certain wavelengths alone will have an outstanding impact on photosynthesis if the spectrum is not balanced properly. Especially when the additional wavelengths come from monochromatic diodes. Research seems to agree with this view.
Photosynthetic Physiology of Blue, Green, and Red Light: Light Intensity Effects and Underlying Mechanisms - PMC
Red and blue light are traditionally believed to have a higher quantum yield of CO2 assimilation (QY, moles of CO2 assimilated per mole of photons) than green light, because green light is absorbed less efficiently. However, because of its lower ...
This, IMO, is why red heavy spectrums often aren’t the “best” for growing, or at least don’t offer the growth benefits that many claim. Imbalance.
This is a great study from 2022 about testing different wavelengths/combinations of light at varying flux levels.
“Modulations in Chlorophyll a Fluorescence Based on Intensity & Spectral Variations in Light”
Modulations in Chlorophyll a Fluorescence Based on Intensity and Spectral Variations of Light - PMC
Photosynthetic efficiency is significantly affected by both qualitative and quantitative changes during light exposure. The properties of light have a profound effect on electron transport and energy absorption in photochemical reactions. In ...
Youre judging a spectrum on the inclination of that line that connects red peak to blue peak, and if i understand you correctly, the more horizontal it slopes the better or the more it slopes up on the right side the better? Cause the downwards slope of the 5k 80cri is not desirable.
What follows from that argument is that adding more red, or blue, wont change how effective the spectrum is as long as it doesnt change the proportions of the highest peaks? Could you fill out the whole section of the spectrum between 400-450nm with blue light of half the intensity of the 450 peak with no effect?
You talk about Chloro A absortion peaks; in the previous case, 450 peak and half intensity on anything between the peak of 450 and 400, would one be using the peak of 450nm or should one use the values at around 430 to draw that line?
Sorry i dont mean to call you out, i just dont understand exactly what youre saying.
Also, it may be that you and prawn are talking about different things, hes talking about flower yield while you seem to talk about photosynthetic efficiency of a certain spectrum. But that kinda forgets about the plants morphogenetic reactions to the spectrum; a red heavy spectrum, including some far red, may make the plant redirect more energy towards budding/flowers than what you would gain in using a photosynthetically more efficient spectrum at same intensity.
Rocket Soul
Well-Known Member
Another point id like to mention for discussion: has anyone evaluated the difference in how a led spectrum performs depending on how it is created? As in: is there a difference in growth characteristics depending on if this red in the spectrum is coming from a few red sup diodes or if its coming from the white diodes?
cdgmoney250
Well-Known Member
I did note that you had mentioned it, which was kind of the point I was trying to make. The study cited is fairly disingenuous when comparing those two types of LED chips and expecting to get meaningful interpretations of how spectrum can effect photosynthesis and yield, considering one of the chips (80CRI) would be known to perform worse by just about anybody with a horticultural background just looking at the spectrum graphs. The 80CRI chip hardly covers the red end where chlorophyll a excitation would be taking place.
It’s an apples to oranges comparison in my opinion, one of which the author of the study with their team of scientists should have been able to distinguish.
Not only was the Hortisolis chip competing against a photosynthetically inferior spectrum, but the lighting conditions were considered to be low ppfd. As mentioned in both of the studies I had linked, the photosynthetic efficiency of different spectra change and vary under increasing flux conditions. Nobody is growing cannabis at 200-300 ppfd.
Not to say the study is worthless by any means, but I might need a tablespoon of salt with any conclusions drawn from it relating to high flux grown cannabis.
One more issue I have with that study is the fact that it is being completed by a chip manufacturer as the thesis to promoting chip technology that they would like to sell to the world market. It only behooves the manufacturer/author of the study if their chips are shown in a favorable light (pun intended), when compared to others. Which in my opinion is why they chose to compete against a spectrum they knew would be photosynthetically inferior. My point is that this conclusion is disingenuous.
Why would the company come out with this chip? I would guess because there is a void in White LED’s that cover much of the red end of the spectrum and research science progresses faster than chip R&D. I’m sure the Hortisolis chip works just fine for general photosynthesis,especially compared to a 5000k (80CRI) chip.
EDIT:
I also believe there is a huge user market for Horticultural LED chips, either new lighting or to replace traditional lighting tech. Because the vast majority of LED chips are used for human-centric lighting, a manufacturer would have a real advantage if they had a “plant specific” led chip that could be marketed as more efficient and more productive than the usual lumen chips. I would just like to see the Hortisolis trialed against a more plant suited spectrum, at higher ppfd before declaring a new spectrum winner.
I’m familiar with the Emerson effect. The problem is that the Emerson effect doesn’t take place under low light conditions. As you mentioned it is a cooling system (regarding electron excitation) to reduce the effects of photo-inhibition, which typically only occur under high ppfd/high temperature conditions.
EDIT: it would be interesting to know at what ppfd levels either spectrum induced visible stress. Can plants under the Hortisolis spectrum photosynthesize at a higher ppfd? If so, how much of that could you assign to the Emerson effect vs different spectrum ratios?
Now, if we are talking morphological changes in plant structure regarding far red, I’m on board with you. It becomes a matter of what changes occur at different R:FR ratios and flux densities vs control? Do these changes positively or negatively influence yield/cannabinoid content? That would be a study I could put some weight against.
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