What would you pick led or hps?

It might lead to better lights and better weed if the light manufacturers start to make lights that have programmable and separate channels for each color band. That way, growers could simulate the way the Earth's atmosphere changes the colors of refracted sunlight according to weather and seasonal conditions in a similar way that nature does it.

It is my understanding that the sun acts more like an induction coil as it passes over the atmosphere. The noble gasses in the sky become exited, and light up different colors just like when you put the same gasses in test tubes for a science experiment. I'm convinced the sun is causing the sky to become a second source of light, kinda like how the auroras happen even though the sun is far away..

BTW, they say the atmosphere extends way out past the moon into space now.

tstick said:

It might lead to better lights and better weed if the light manufacturers start to make lights that have programmable and separate channels for each color band. That way, growers could simulate the way the Earth's atmosphere changes the colors of refracted sunlight according to weather and seasonal conditions in a similar way that nature does it.

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We won't even need light to grow in the future. Just pickup a tank of cannabis friendly acetates and plug it into your artificial grow pod.

tstick said:

It might lead to better lights and better weed if the light manufacturers start to make lights that have programmable and separate channels for each color band. That way, growers could simulate the way the Earth's atmosphere changes the colors of refracted sunlight according to weather and seasonal conditions in a similar way that nature does it.

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Not really. They have that for aquarium lights and one of the following things does happen:
You choose the settings of someone you trust and be done with
You fiddle with it every 2 weeks

In any case you will never reach an optimum. Neither do you get any benefit.

That would require controlled tests. Controlled means you have to compare it to something. So half the crop has to be generic, unoptimized. And we don't have the space or money to use suboptimal settings for a significant portion of the crop. Neither do home growers have access to the required testing to confirm if one is better.
The light would be much for expensive though. You need multiple drivers, an app to control it, customer support to help people who just need any reasonable setting and it has to be overpowered because you don't run everything at 100 %.

Some well placed mirrors on the roof and a bundle of optic fibers and you don't need electric lighting at all. And the color change is automatic!

Saying there would be no benefit or measurable plant responses from a full changing spectrum compared to a control spectrum is a bold statement, considering that’s what plants evolved under. I personally don’t think it would be difficult to achieve. There are already plug and play light controllers that can ramp up drivers on a predetermined or custom schedule. You would just need that same capability over 1-2 other driver channels and you have yourself sunrise/midday/sunset functions changing spectrum and intensity.

Oh, and if manufacturers started using daylight LED’s that covered the visible spectrum more broadly/evenly, I personally bet the plants would notice. Maybe throw some 680nm and a few 700nm diodes in the mix.

Any commercial medical/recreational growers has all the testing and lab access once would need to determine if a difference is made. I’d bet money there would be measurable differences in either bud size, bud density, cannabinoid content, or terpene content between a changing spectrum and controlled fixed spectrum given the same overall DLI.

cdgmoney250 said:

considering that’s what plants evolved under

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So what?
My ancestors evolved in the desert and died being 30. I live in a house and will die being 90.
You don't have to make your lighting worse because plants evolved so.
However, only testing will reveal the truth.

Rennpappe said:

So what?
My ancestors evolved in the desert and died being 30. I live in a house and will die being 90.
You don't have to make your lighting worse because plants evolved so.
However, only testing will reveal the truth.

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The science was explained to you and you just argue. We aren't doing that. You're just disrupting the thread. Please stop, thanks.

Rennpappe said:

So what?….…. You don't have to make your lighting worse because plants evolved so…..

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From Wikipedia’s definition of evolution regarding natural selection:

Evolution by natural selection is established by observable facts about living organisms: (1) more offspring are often produced than can possibly survive; (2) traits vary among individuals with respect to their morphology, physiology, and behavior; (3) different traits confer different rates of survival and reproduction (differential fitness); and (4) traits can be passed from generation to generation (heritability of fitness).[7] In successive generations, members of a population are therefore more likely to be replaced by the offspring of parents with favorable characteristics for that environment.

Can you please explain how getting artificial lighting closer to mimicking natural sunlight is in fact making it “worse” than the “grow spectrums” we have available to us today?

cdgmoney250 said:

Can you please explain how getting artificial lighting closer to mimicking natural sunlight is in fact making it “worse” than the “grow spectrums” we have available to us today?

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Natural conditions are not obivously better. It can be too hot with all that IR, half of the mechanisms inside a cell are occupied repairing damage from photooxidation and there are even pathways to directly turn light into heat before it causes damage (non photosynthetic quenching).
Also, what is 'sunlight' anyways? It changes depending on weather, time of day, season and longer cycles such as distance from the sun and the cycle of the sun. Both in intensity and spectrum on time scales from seconds to decades.

Sure, you can find something better than using the standard white + red LEDs. This is in fact an improvement in both cost and performance over the blurple that were used before.
But how would you do it? Say you have 3 channels of light, want to measure at 3 intensities and replicate each trial. That is 18 crops you have to run. Who will pay for that?

cdgmoney250 said:

Saying there would be no benefit or measurable plant responses from a full changing spectrum compared to a control spectrum is a bold statement, considering that’s what plants evolved under. I personally don’t think it would be difficult to achieve. There are already plug and play light controllers that can ramp up drivers on a predetermined or custom schedule. You would just need that same capability over 1-2 other driver channels and you have yourself sunrise/midday/sunset functions changing spectrum and intensity.

Oh, and if manufacturers started using daylight LED’s that covered the visible spectrum more broadly/evenly, I personally bet the plants would notice. Maybe throw some 680nm and a few 700nm diodes in the mix.

Any commercial medical/recreational growers has all the testing and lab access once would need to determine if a difference is made. I’d bet money there would be measurable differences in either bud size, bud density, cannabinoid content, or terpene content between a changing spectrum and controlled fixed spectrum given the same overall DLI.

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Unfortunately rising energy costs and enviro bs has won out so umole/joule has become the dominant factor influencing the horticultural lighting industry. Not necessarily plant health / quality

Lou66 said:

Not really. They have that for aquarium lights and one of the following things does happen:
You choose the settings of someone you trust and be done with
You fiddle with it every 2 weeks

In any case you will never reach an optimum. Neither do you get any benefit.

That would require controlled tests. Controlled means you have to compare it to something. So half the crop has to be generic, unoptimized. And we don't have the space or money to use suboptimal settings for a significant portion of the crop. Neither do home growers have access to the required testing to confirm if one is better.
The light would be much for expensive though. You need multiple drivers, an app to control it, customer support to help people who just need any reasonable setting and it has to be overpowered because you don't run everything at 100 %.

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We know the impact of different spectra. Blue photons make plants short, compact, thick stems, lots of small leaves, and short internodal space . Red light is used because it's highly efficient, in terms of photons per watt. That information is freely available and there's no mystery to it.

After using a Mars SP 3000 for a couple of grows, I bought veg and flower LED's and I use those, as well as two others, in the course of a grow. The reason - because it allows me to control the shape of the plant.

When I bought those lights, HLG and Chilled (Growcraft) were the only two LED's manufacturers making "separates". As of late last year, Chilled has gone to white + far red. Paraphrasing Guy Kawasaki, "If you have the market to yourself, you don't have a market."

The market is demanding white + far red because white LED's have enough blue to provide the benefits of blue photons, white LED's are cheap to manufacture, and far red + deep red photons work synergistically to increase the rate of photosynthesis that exceeds the increased number of photons.

Underlying that is that, per Bugbee, the "quality" (color) of a light shapes a plant but the quantity of light drives yield. Again, there's scads of evidence to substantiate this. More photons = more yield (all other things being equal and it light is the limiting factor).

Some companies are selling light with a tunable spectrum. I think that FOHSE makes a tunable light and I know that Kind does, as well. Interestingly, Kind goes to some lengths to not disclose their PPFD map. That's completely understandable — whether they actually believe it or not, their marketing is that their tunable spectrum light is a superior product so that's what they push it.

Lou66 said:

Natural conditions are not obivously better. It can be too hot with all that IR, half of the mechanisms inside a cell are occupied repairing damage from photooxidation and there are even pathways to directly turn light into heat before it causes damage (non photosynthetic quenching).
Also, what is 'sunlight' anyways? It changes depending on weather, time of day, season and longer cycles such as distance from the sun and the cycle of the sun. Both in intensity and spectrum on time scales from seconds to decades.

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We don't make grow lights that mimic the sun because there's no evidence that plants use light outside of the range of 400 to 730nm. That's why it's called photosynthetically active radiation.

Lou66 said:

Sure, you can find something better than using the standard white + red LEDs. This is in fact an improvement in both cost and performance over the blurple that were used before.
But how would you do it? Say you have 3 channels of light, want to measure at 3 intensities and replicate each trial. That is 18 crops you have to run. Who will pay for that?

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Words like "better" is undefined so the discussion can turn into a fight over what "better" means.

White + far red provides a modicum of blue, enough green to allow humans to see the plants, a lot of red, which increases the electrical efficiency of the fixture, and far red for its synergy with deep red.

That's what I see in the marketplace and it's almost word for word from the video interview that Shane @ Migro and Bugbee released about a month ago.

Re. blurple - My screen name is the reversed abbreviation for an 8 square foot tent, a SuperPonics reservoir, and an LED. Back in 2017, it was a Kind blurple. I did one grow in 2017 and started up again in 2021 — LED's had changed quite a bit in those four years. I contacted Kind for a PPFD map and, upon receipt, put the Kind in the trash and bought a Mars SP 3000. The PPFD map for the Kind and the Mars are attached.

The Mars design is from 2020±. The Kind is from 2015 or 2106. That's, call it, 5 years. Five years from now? Who knows?

Rennpappe said:

No.
For years I also thought that the red setting sun must have something to do with the atmosphere acting as a prism. Because it's kind of logic and if you make a drawing of it it kind of looks the same.
But then after I did some research I found out the red setting sun has nothing to do with a prism like atmosphere.
So it's not semantics; it's research and physics.


This is complete BS.
Air is filled with gaseous water, not liquid water. Liquid water is present in clouds and rain. Liquid water is visible, gaseous water is not.
You're messing it up even more.

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when is water considered a liquid when a vapor? how big does a droplet need to be? vapor and liquid is the same shit just molecules are spaced more

Lou66 said:

Natural conditions are not obivously better.

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Natural Conditions are not what I’m proposing. I’m taking about optimizing the controlled grow environment using as close to a “Sunlight Spectrum” as possible (this also means a variable spectrum).


This means if plants get stressed out above 1800+ ppfd, then don’t allow the plants to receive that much light (dim or raise light). If the soil is dry, water it. If the air is too dry, adjust the humidity.

Lou66 said:

Also, what is 'sunlight' anyways?

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Because cannabis is an annual plant, I would say the sunlight we should concern ourselves with is the spectrum of sunlight from spring through autumn. The spectrum changes throughout the day as we know. But it’s fairly similar across the globe on sun days depending on location and local season.

these are reading


Below are measurements throughout a full day from different locations and different zenith angles



And below is a shot of the spectrum just before and after sunset


As one can see,the spectrum that a plant receives on a given day outside might resemble a “veg” spectrum and a “bloom” spectrum throughout a 12-14 hr period. Daily. The primary differences (regarding spectrum) that change through out the season is how long plants are exposed to the each variation in the spectrum. Days are longer during spring leading up to summer. This means plants receive more midday spectrum for longer durations until the days start getting shorter.

Lou66 said:

Not really. They have that for aquarium lights and one of the following things does happen:
You choose the settings of someone you trust and be done with
You fiddle with it every 2 weeks

In any case you will never reach an optimum. Neither do you get any benefit.

That would require controlled tests. Controlled means you have to compare it to something. So half the crop has to be generic, unoptimized. And we don't have the space or money to use suboptimal settings for a significant portion of the crop. Neither do home growers have access to the required testing to confirm if one is better.
The light would be much for expensive though. You need multiple drivers, an app to control it, customer support to help people who just need any reasonable setting and it has to be overpowered because you don't run everything at 100 %.

Click to expand...

It's impossible to do controlled tests when the subject is as variable as commercial marijuana. You'd have to have just one cultivar and test it over and over. And then what good would that data be unless there was only one cultivar of commercial marijuana?
Having a light that a grower could dial in their own spectral formula for each cultivar would be great.
As far as what it would take to build such lights....wellll just look at what happened with LEDs over the last 10 years. I think the technology will get there.
I can't see what other avenue light manufacturers will have left to go down, when literally every product nowadays has Samsung chips and Meanwell drivers -or the equivalent. What else can a manufacturer do when all things (other than price) becomes equal? More companies are going to have to start incorporating separate channels and allowing growers to "mix" their own spectrums....for better or worse.

cdgmoney250 said:

Natural Conditions are not what I’m proposing. I’m taking about optimizing the controlled grow environment using as close to a “Sunlight Spectrum” as possible (this also means a variable spectrum).


This means if plants get stressed out above 1800+ ppfd, then don’t allow the plants to receive that much light (dim or raise light). If the soil is dry, water it. If the air is too dry, adjust the humidity.



Because cannabis is an annual plant, I would say the sunlight we should concern ourselves with is the spectrum of sunlight from spring through autumn. The spectrum changes throughout the day as we know. But it’s fairly similar across the globe on sun days depending on location and local season.

these are reading
View attachment 5380626

Below are measurements throughout a full day from different locations and different zenith angles

View attachment 5380627

And below is a shot of the spectrum just before and after sunset
View attachment 5380628

As one can see,the spectrum that a plant receives on a given day outside might resemble a “veg” spectrum and a “bloom” spectrum throughout a 12-14 hr period. Daily. The primary differences (regarding spectrum) that change through out the season is how long plants are exposed to the each variation in the spectrum. Days are longer during spring leading up to summer. This means plants receive more midday spectrum for longer durations until the days start getting shorter.

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And what happens on overcast days, rainy days or when a cloud shows up? What happens when in 30 years the average DLI is lower or higher? Considering that ideal DLI is dependent on CO2 levels, which do you use? Curent levels or what we had ~100 years ago, which was 30 % less?

After clearing that up can you propose experiments that will get you to your desired goal. From what I understand you want to not only have a variable spectrum but multiple spectrums per plant. Do you want steep gradients when changing between those and if not what rate of change? How long to apply each spectrum?

Let's just look at the numbers for a full factorial design:
Five different spectrums changing five times per day, in all orders, at 3 different rates of change, at 5 different intensities, changing up to five times, in all orders per day at 3 different rates of change. Each replicated once.
((5*(5*5)*3)*(5*(5*5)*3))*2=93,750

Then we want to test influence of fertility, abiotic factors, genetics and disease and pest resistence too.

cdgmoney250 said:

I’m taking about optimizing the controlled grow environment using as close to a “Sunlight Spectrum” as possible (this also means a variable spectrum).

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Either you do a sunlight spectrum or you don't. "sticking as close to sunlight as possible but deviating where it gives better results" is the same as being vegan every time you don't eat animal produce.

tstick said:

You'd have to have just one cultivar and test it over and over. And then what good would that data be unless there was only one cultivar of commercial marijuana?

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I'm glad you understood my point.

tstick said:

Having a light that a grower could dial in their own spectral formula for each cultivar would be great.

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And what would you specifically set it to? Remember, you just said that you can't really transfer knowledge from one cultivar to the next.

Lou66 said:

I'm glad you understood my point.


And what would you specifically set it to? Remember, you just said that you can't really transfer knowledge from one cultivar to the next.

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I'm not sure. But, I guess I'd do some experimentation. I can't get close to knowing what conditions that every cultivar out there would thrive under but I think it would be fun to screw around with ideas.
I'd probably start out with something that looked like MH color and then start adding or subtracting reds and yellows depending on the growth stage until I got to something closer to HPS. Or, maybe I'd try something really stupid, like all yellow, just to see what would happen!
I think it would be really cool to be able to program spectral shifts over the course of a "lights on" period, too. Like, the lights would be blue at the beginning and red at the end of the "day"....maybe have it be on some kind of smart timer that turns things off/on and up/down all in the same operation.

EDIT: And, wouldn't you only need three channels? Red, Blue and Yellow.....right? And some way to mix the levels of each, of course.

Lou66 said:

And what happens on overcast days, rainy days or when a cloud shows up? What happens when in 30 years the average DLI is lower or higher? Considering that ideal DLI is dependent on CO2 levels, which do you use? Curent levels or what we had ~100 years ago, which was 30 % less?

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Plants grow under light more so than not. Many studies have shown that increasing DLI has a positive correlative influence to plant growth, when mitigating stress. I’m proposing a cloudless season, where irrigation replaces rain. Again this hypothetical is in a controlled growing environment.

Lou66 said:

Either you do a sunlight spectrum or you don't. "sticking as close to sunlight as possible but deviating where it gives better results" is the same as being vegan every time you don't eat animal produce.

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If I could legally grow in a fully equipped, climate controlled, light deprivation greenhouse in my backyard, I wouldn’t care much about LEDs and “indoor”growing.

If you have some links to some 380nm-780nm LED chips that have a true sun imitating spectrum for for each hour of the day, please post the links and help a brother out. Otherwise, as a hobbyist non-academic pot grower, I think I’ll have to make do with the chips I have available to me. Which seemingly nobody else is using in grow fixtures, because the ppf/joule won’t be high enough.

If the plants perform “better” (there’s that word again) under a broader spectrum compared to a run of the mill “grow” spectrum, for similar electrical usage, then that’s a win in my book. If plants perform ”better” under a changing broad spectrum, than a static broad spectrum, that would be another win. That’s all I want to know.