Unlocking Cannabis’ Full Potential: The Case For and Against UV Scynce Led Light UV Cannabis Relation What is the true UV and Cannabis relation?

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DonnainTripp

DonnainTripp

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There are few more heated topics in the cannabis industry than the potential of UV light to improve the quality of cannabis plants. Some growers insist that it is an undeniable fact that UV is necessary to grow high quality cannabis, period. The demonstrable data to date, however, is minimal at best. While there have been a handful of good studies conducted on UV light and cannabis, on the whole, their results are inconclusive and unremarkable.

This begs the question, “Why are so many cannabis growers certain that they need UV to achieve that ‘fire’ bud?” The answer lies in a scientific exploration of UV light and how it influences plant morphology. All light consists of particles traveling in waves, and the distance between them, or the wavelength, determine the light’s properties. UV wavelengths cover a range of 100-400 nanometers (nm). UV-A light, at 315-400nm, has the longest wavelengths of the group. At 280-315nm, UV-B has shorter wavelengths and UV-C has the shortest at 100 – 280nm. In nature, plants encounter mostly UV-A and some UV-B. UV-C wavelengths, being so short, are mostly absorbed by the atmosphere and rarely make it to the ground.

The first question is, “Why is there such an industry wide belief that UV light is needed in the first place?” When plants of any type encounter UV, they produce stress responses that trigger protection mechanisms. Just as humans use sunscreen to protect themselves from the harmful rays of the sun (UV-A and UV-B), plants produce secondary compounds like anythrocynine to protect themselves from these same damaging UV wavelengths.

As cannabis growers, many of us find this response alluring. On the surface, the concept of more purples and secondary compounds such as anythrocynine seem likely to lead to a better terpene and cannabinoid suite in our final product. The science, however, indicates that UV and Cannabis relation effects are minimal at best. Yes, we get more vibrant colors and possibly better trichome head production as well. Ironically though, it seems this can also be achieved with any full spectrum LED on the market without the extra stressor of UV light. As the scientific studies are lacking here, anecdotal stories and results are all that we can rely on today.

The Claims on UV and Cannabis relation
The claims surrounding UV are widespread enough that it is worth exploring some of them. Of highest interest is the idea that UV-A and UV-B contribute to an increased production of THC in the plant. Science, fundamentally, still hasn’t come to any conclusions on this. Some strains, like OG landrace crosses and cannabis strains from traditionally high-UV areas around the globe have shown some bumps in THC production and secondary cannabinoids. Hemp CBD cultivars, on the other hand, have shown increases in secondary compound production. Overall, today’s indoor, exotic, multiple-cross cultivars have shown no great response to the introduction of UV as a minor stressor. As breeding moves further away from natural outdoor genetics, the added UV can actually cause negative effects for plants that have never been exposed to these types or levels of stressors.

Another claim is that UV-A and UV-B produce more trichomes and more complete heads on the trichomes, creating a frostier looking flower. The jury is still out on this one. Current research into this is in its beginning stages and most of the work so far has been done on hemp. Personally, in my time working with growers around the country, I have heard many stories about better returns on washing hash when UV-A or UV-B was introduced during the grow cycle. Again, there is little hard evidence to these claims though. What this could mean is that we are seeing better structure from our trichomes, just maybe not more of them.

As our research into cannabis continues, we hope to see more data come out of future experiments. Bruce Bugbee has a project underway looking very closely at cannabis’ response to UV-A and UV-B and the UV and Cannabis relation. In a recent interview, shedding some light on his current work, he suggested some of the early research from heavy blues (400-450nm), just short of the UV-A spectrum, were showing similarly beneficial effects.

An additional question we must ask is why are we not seeing more LED light manufacturers adding UV to the fixtures? With UV-A being 50-100x the cost of a full spectrum white or even a deep red LED, the cost for UV is definitely prohibitive. For a manufacturer to include this in every light they sell, it gives pause and begs the question of its validity and value. Especially as we look at commercial facilities who are purchasing hundreds of lights, is there enough evidence (as of the publishing of this article there is not) to support the increased cost?

UV and Cannabis relation and cost impact
Some studies are starting to look into the UV and Cannabis relation and show that UV-A (365nm) and UV-B in small doses or cycles are what really trigger photomorphogenesis within plants, especially cannabis. If these results are proven true, it would mean that UV should not be built-in to LED fixtures unless they have control over it through spectrum tuning or channel control. Interestingly, most LED fixtures on the market today that have UV built-in, have UV-A (395nm), which has yet to be shown any more effective than blue LEDs in the 400-450nm range. As a cautionary note, both UV-B and UV-C must be used with extreme caution around humans and it makes it virtually impossible to have either of these spectrums built-in to an everyday grow light.

Is UV Worthy of All The Hype?
Does this mean we should or shouldn’t invest in UV? Like any other choice you make as a grower, it completely depends on what you are looking to achieve within your grow and with your plants. Depending on your grow style, spending the extra money on a UV fixture may or may not get the result you’re looking for.

Let’s start with our hydroponic growers, which includes anyone with inert media or water based set-ups (since there are many different ways on how to work with coco coir, it is included both here and with the soil media). Hydro/salt growers should have complete control over the nutrients and uptake for their plants. This means they can accomplish a “dialed-in” setup, where ideal uptake and nutrient availability is achieved. Adding UV-A or UV-B to these very low stress environments is probably the most effective application. Anecdotally, we typically see a 3%-5% bump in overall quality (quality = increased terpenes/cannabinoids and/or bag appeal; typically not weight). It is worth emphasizing though that this only applies if you are reaching maximum output from your current setup before adding in UV.

Soil and organic coco coir growers have some secondary things to consider. First and foremost, multiple studies have shown UV-B can degrade organic additions. Bacteria and fungal communities can be impacted and have been shown to actively avoid high UV-B areas. Research also shows that arthropods will be pushed further into the canopy or media to avoid the high UV-B light (more on this later). Secondarily, ask yourself if you’re getting 100% out of your plants already. Is that 3-5% bump from minor stressors going to be worth compromising your additions?

These growers will probably tell you that the color structure and flavor are better than those produced with salts. Will the UV-A and UV-B be that golden key to the production you are already achieving? More times than not the answer to that will likely be no.

UV and Cannabis relation IPM Alert
The Dangerous Side of UV
Finally, let’s touch on UV-C. This wavelength is mostly used in clean-lights and to purify air for indoor areas. It’s a great tool for cleaning and removing contaminants from a grow environment. It can be beneficial as a direct leaf application to control certain types of powdery mildew. It is important to note that the amount of tissue damage from UV-C on leaves and buds is not always worth the help, and long exposure to UV-C or UV-B has been shown to adversely affect plant tissue. It creates an almost burned look on buds and leaves an opening to a secondary invasion from pathogens.

Final Verdict on UV and Cannabis Relation
So, what’s the verdict on the UV and Cannabis relation? It depends! For starters, there has yet to be scientific proof that UV-A adds more value than deep blue (400-450nm) light. If you are growing for terpene or hash production in a hydroponic environment, it may very well be worth experimenting with blue (430nm), UV-A or UV-B to see how it might enhance quality. If you are an organic/soil grower, the addition of UV, given the positive and negative trade offs, may not bring enough value to introduce it into your grow. UV-C should be used in air cleaning devices yet left out of most grow environments, as the impacts on plants and humans alike keeps this in a do-not-use category.

At the end of the day there’s no free lunch and no silver bullet. UV-A, B and C have their advantages and value adds, but they all come at a cost. Just like most things in life, the overall cultivation strategy you employ requires a holistic approach with a defined goal in mind to maximize the outcomes. UV won’t magically change anything and may just be the type of disruption you are trying to avoid. Remember, the devil is truly in the details, especially when it comes to the UV and Cannabis relation.

Greg Selby
Director of Cultivations Sciences, Scynce LED
Specialist in IPM Strategies & Soil Ecology
 
Z

Zill

371
63
DonnainTripp

DonnainTripp

21
3
I'm still looking for a good uva light bar to toss in my tent with my rspec and cree cobs but dam those are still running over 200.00 and I'm not buying Amazon lights , was looking at black dog but still over 2 grand, so I'm just gonna add to mine that way I can run them in cycles. Heard it's better that way but keep me posted and I'll do same and we'll figure out witch is better together. Keep me posted
 
Z

Zill

371
63
Donnain,

I know it sounds nutso, but those 75W reptile UV-B lights will provide enough radiation for a good size tent. I worked out the wattage and surface area. I can send that if you're interested.

Zill.
 
DonnainTripp

DonnainTripp

21
3
Donnain,

There is no UV hype. The heated discussions are led by the uniformed. Attached is the original research article that defines UV and the effects on flavonoid, terpenoid and cannabinoid synthesis.


Zill.
Thanks zill still researching, so this isn't my opinion just me fishing for more info from experienced growers that have integrated uv and ir with the full spectrum, just waiting to find some uva's to add to my hlg to try it and see for myself but still info diving to figure out the best uv lights to add and the best way to set up in my 4 x4 and to run em , with intervolt timers or just run with 12/12 so any info on this would be much appreciated thank you
 
PipeCarver

PipeCarver

Supporter
4,748
263
There are few more heated topics in the cannabis industry than the potential of UV light to improve the quality of cannabis plants. Some growers insist that it is an undeniable fact that UV is necessary to grow high quality cannabis, period. The demonstrable data to date, however, is minimal at best. While there have been a handful of good studies conducted on UV light and cannabis, on the whole, their results are inconclusive and unremarkable.

This begs the question, “Why are so many cannabis growers certain that they need UV to achieve that ‘fire’ bud?” The answer lies in a scientific exploration of UV light and how it influences plant morphology. All light consists of particles traveling in waves, and the distance between them, or the wavelength, determine the light’s properties. UV wavelengths cover a range of 100-400 nanometers (nm). UV-A light, at 315-400nm, has the longest wavelengths of the group. At 280-315nm, UV-B has shorter wavelengths and UV-C has the shortest at 100 – 280nm. In nature, plants encounter mostly UV-A and some UV-B. UV-C wavelengths, being so short, are mostly absorbed by the atmosphere and rarely make it to the ground.

The first question is, “Why is there such an industry wide belief that UV light is needed in the first place?” When plants of any type encounter UV, they produce stress responses that trigger protection mechanisms. Just as humans use sunscreen to protect themselves from the harmful rays of the sun (UV-A and UV-B), plants produce secondary compounds like anythrocynine to protect themselves from these same damaging UV wavelengths.

As cannabis growers, many of us find this response alluring. On the surface, the concept of more purples and secondary compounds such as anythrocynine seem likely to lead to a better terpene and cannabinoid suite in our final product. The science, however, indicates that UV and Cannabis relation effects are minimal at best. Yes, we get more vibrant colors and possibly better trichome head production as well. Ironically though, it seems this can also be achieved with any full spectrum LED on the market without the extra stressor of UV light. As the scientific studies are lacking here, anecdotal stories and results are all that we can rely on today.

The Claims on UV and Cannabis relation
The claims surrounding UV are widespread enough that it is worth exploring some of them. Of highest interest is the idea that UV-A and UV-B contribute to an increased production of THC in the plant. Science, fundamentally, still hasn’t come to any conclusions on this. Some strains, like OG landrace crosses and cannabis strains from traditionally high-UV areas around the globe have shown some bumps in THC production and secondary cannabinoids. Hemp CBD cultivars, on the other hand, have shown increases in secondary compound production. Overall, today’s indoor, exotic, multiple-cross cultivars have shown no great response to the introduction of UV as a minor stressor. As breeding moves further away from natural outdoor genetics, the added UV can actually cause negative effects for plants that have never been exposed to these types or levels of stressors.

Another claim is that UV-A and UV-B produce more trichomes and more complete heads on the trichomes, creating a frostier looking flower. The jury is still out on this one. Current research into this is in its beginning stages and most of the work so far has been done on hemp. Personally, in my time working with growers around the country, I have heard many stories about better returns on washing hash when UV-A or UV-B was introduced during the grow cycle. Again, there is little hard evidence to these claims though. What this could mean is that we are seeing better structure from our trichomes, just maybe not more of them.

As our research into cannabis continues, we hope to see more data come out of future experiments. Bruce Bugbee has a project underway looking very closely at cannabis’ response to UV-A and UV-B and the UV and Cannabis relation. In a recent interview, shedding some light on his current work, he suggested some of the early research from heavy blues (400-450nm), just short of the UV-A spectrum, were showing similarly beneficial effects.

An additional question we must ask is why are we not seeing more LED light manufacturers adding UV to the fixtures? With UV-A being 50-100x the cost of a full spectrum white or even a deep red LED, the cost for UV is definitely prohibitive. For a manufacturer to include this in every light they sell, it gives pause and begs the question of its validity and value. Especially as we look at commercial facilities who are purchasing hundreds of lights, is there enough evidence (as of the publishing of this article there is not) to support the increased cost?

UV and Cannabis relation and cost impact
Some studies are starting to look into the UV and Cannabis relation and show that UV-A (365nm) and UV-B in small doses or cycles are what really trigger photomorphogenesis within plants, especially cannabis. If these results are proven true, it would mean that UV should not be built-in to LED fixtures unless they have control over it through spectrum tuning or channel control. Interestingly, most LED fixtures on the market today that have UV built-in, have UV-A (395nm), which has yet to be shown any more effective than blue LEDs in the 400-450nm range. As a cautionary note, both UV-B and UV-C must be used with extreme caution around humans and it makes it virtually impossible to have either of these spectrums built-in to an everyday grow light.

Is UV Worthy of All The Hype?
Does this mean we should or shouldn’t invest in UV? Like any other choice you make as a grower, it completely depends on what you are looking to achieve within your grow and with your plants. Depending on your grow style, spending the extra money on a UV fixture may or may not get the result you’re looking for.

Let’s start with our hydroponic growers, which includes anyone with inert media or water based set-ups (since there are many different ways on how to work with coco coir, it is included both here and with the soil media). Hydro/salt growers should have complete control over the nutrients and uptake for their plants. This means they can accomplish a “dialed-in” setup, where ideal uptake and nutrient availability is achieved. Adding UV-A or UV-B to these very low stress environments is probably the most effective application. Anecdotally, we typically see a 3%-5% bump in overall quality (quality = increased terpenes/cannabinoids and/or bag appeal; typically not weight). It is worth emphasizing though that this only applies if you are reaching maximum output from your current setup before adding in UV.

Soil and organic coco coir growers have some secondary things to consider. First and foremost, multiple studies have shown UV-B can degrade organic additions. Bacteria and fungal communities can be impacted and have been shown to actively avoid high UV-B areas. Research also shows that arthropods will be pushed further into the canopy or media to avoid the high UV-B light (more on this later). Secondarily, ask yourself if you’re getting 100% out of your plants already. Is that 3-5% bump from minor stressors going to be worth compromising your additions?

These growers will probably tell you that the color structure and flavor are better than those produced with salts. Will the UV-A and UV-B be that golden key to the production you are already achieving? More times than not the answer to that will likely be no.

UV and Cannabis relation IPM Alert
The Dangerous Side of UV
Finally, let’s touch on UV-C. This wavelength is mostly used in clean-lights and to purify air for indoor areas. It’s a great tool for cleaning and removing contaminants from a grow environment. It can be beneficial as a direct leaf application to control certain types of powdery mildew. It is important to note that the amount of tissue damage from UV-C on leaves and buds is not always worth the help, and long exposure to UV-C or UV-B has been shown to adversely affect plant tissue. It creates an almost burned look on buds and leaves an opening to a secondary invasion from pathogens.

Final Verdict on UV and Cannabis Relation
So, what’s the verdict on the UV and Cannabis relation? It depends! For starters, there has yet to be scientific proof that UV-A adds more value than deep blue (400-450nm) light. If you are growing for terpene or hash production in a hydroponic environment, it may very well be worth experimenting with blue (430nm), UV-A or UV-B to see how it might enhance quality. If you are an organic/soil grower, the addition of UV, given the positive and negative trade offs, may not bring enough value to introduce it into your grow. UV-C should be used in air cleaning devices yet left out of most grow environments, as the impacts on plants and humans alike keeps this in a do-not-use category.

At the end of the day there’s no free lunch and no silver bullet. UV-A, B and C have their advantages and value adds, but they all come at a cost. Just like most things in life, the overall cultivation strategy you employ requires a holistic approach with a defined goal in mind to maximize the outcomes. UV won’t magically change anything and may just be the type of disruption you are trying to avoid. Remember, the devil is truly in the details, especially when it comes to the UV and Cannabis relation.

Greg Selby
Director of Cultivations Sciences, Scynce LED
Specialist in IPM Strategies & Soil Ecology
Thank you, for that information. It;s good to see the reality over the hype.
 
DonnainTripp

DonnainTripp

21
3
Donnain,

I know it sounds nutso, but those 75W reptile UV-B lights will provide enough radiation for a good size tent. I worked out the wattage and surface area. I can send that if you're interested.

Zill.
Hell yeah cause I've been reading uv a are better then B's but like I said it's all been reading I wanna get and try so I ll know for sure what's what thank so much
 
Z

Zill

371
63
I was a fellow graduate student with the author of that article. I know/saw the research first-hand, reviewed the dissertation. It works.

Zill.
 
M

MasterWatererJeff

27
3
Biosynthesis and oxidation of fats is a major goal of Cannabis production. Most good things in Cannabis are lipoxygenase products. ALL desired compounds in Cannabis are derived from electron transport. How does cbg become Thc? How does the nasty children's Tylenol flavor become the delicious "purp" flavor everyone loves?

UV will damage the plant directly through oxidation, damaging DNA and other functions, and many strains are adapted to produce volatile compounds to intercept these damaging rays. Strains adapted to high altitude and exposed locations often respond to intense UV-B by producing volatiles as a way of protecting cellular products from damage, and these volatiles are typically terpenes, thiols, carboxylic acids and phenylpropanoids. In the absence of volatile antioxidant metabolism such as short chain thiols (skunk, garlic, rubber, boxwood,fruit), you see cyanidin glucosides, antioxidant pigments of zero value to the end user.

Photons from light can cause oxidation, though typically they are low energy, and so require sensitisers in the leaf to begin the first stage of oxidation. If no photosensitizer is present, likewise if no non-volatile precursor is present, UV-B will negatively correlate with quality.


Bonus rant:

Growing outdoors isn't going to unlock the full potential of Cannabis on its own. It is very apparent the biggest obstacle for growers is nutrition. That's step one which every grower skips on their journey to becoming a master Ganjier. Next on the list of obstacles modern growers face would be glycosidic bonds trapping flavor active molecules. 3rd would be the total misconception of curing, ignoring the fact that oxidation is the fundamental process of secondary metabolism in Cannabis. Somewhere down the list is 'cides, the fact people think it's okay to spray growing plants. Don't worry about UV until you can feed your plant properly (which obviously eliminates the need to spray shit).

Grow starchy weed, spray it, keep it wet, put it in a fridge, that's what you end up with: nutrient deficient uncured contaminated incompletely metabolized garbage. Now you wanna add UV because that's how most growers roll: Skip the foundation and build a roof. This is what most folks do or aim to do in the Cannabis scene. Earthy = bad nutrition and no cure. Kush should not smell like dirt and peanuts or taste like tobacco. I have seen it thousands of times. Most growers will never smell or taste their strain as intended, as the natural flavor is held back at every turn; through poor nutrition, through incorrect stressors, through bottled contaminants, through attempts to preserve cannabis as if it were lettuce.. It's extremely disheartening that the Cannabis scene has no desire for quality, only for an accepted religion, with revered priests of ignorance, arbitrary qualifiers and a flock of blind sheep to fit in with.

If you want to know why Cannabis isn't like it used to be, this is why. I see growers skip right to buying a cure fridge 'because terps evaporate' or some similar weird concept that requires either zero thought or major mental gymnastics, combined with a total lack of experience with the plant.
Everyone wants to talk "terps" until someone qualified talks back. There are 1000 times more volatiles locked away in glycosides and amino acids than there are floating off a growing bud at harvest and none of the interesting volatiles are on the "Leaflynene" posters. Not on Leafly terp poster? Who cares, it's not accepted dogma, Mendo Dope hasn't rapped about methoxypyrazines, so those aren't cool enough for the cool kids growing the pot these days, not cool like "terps" are.

Maybe my great grandchildren will actually be able to discuss cannabis with their peers. Or will people still be claiming myrcene causes couch lock, claiming that Rick Simpson oil from shit bud cures cancer and claiming fresh freezing is an acceptable production step for a plant dependent on lysis for metabolism?

Go to patreon for the full length extend bonus rant.
 
Last edited:
Harpua88

Harpua88

Supporter
422
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There are few more heated topics in the cannabis industry than the potential of UV light to improve the quality of cannabis plants. Some growers insist that it is an undeniable fact that UV is necessary to grow high quality cannabis, period. The demonstrable data to date, however, is minimal at best. While there have been a handful of good studies conducted on UV light and cannabis, on the whole, their results are inconclusive and unremarkable.

This begs the question, “Why are so many cannabis growers certain that they need UV to achieve that ‘fire’ bud?” The answer lies in a scientific exploration of UV light and how it influences plant morphology. All light consists of particles traveling in waves, and the distance between them, or the wavelength, determine the light’s properties. UV wavelengths cover a range of 100-400 nanometers (nm). UV-A light, at 315-400nm, has the longest wavelengths of the group. At 280-315nm, UV-B has shorter wavelengths and UV-C has the shortest at 100 – 280nm. In nature, plants encounter mostly UV-A and some UV-B. UV-C wavelengths, being so short, are mostly absorbed by the atmosphere and rarely make it to the ground.

The first question is, “Why is there such an industry wide belief that UV light is needed in the first place?” When plants of any type encounter UV, they produce stress responses that trigger protection mechanisms. Just as humans use sunscreen to protect themselves from the harmful rays of the sun (UV-A and UV-B), plants produce secondary compounds like anythrocynine to protect themselves from these same damaging UV wavelengths.

As cannabis growers, many of us find this response alluring. On the surface, the concept of more purples and secondary compounds such as anythrocynine seem likely to lead to a better terpene and cannabinoid suite in our final product. The science, however, indicates that UV and Cannabis relation effects are minimal at best. Yes, we get more vibrant colors and possibly better trichome head production as well. Ironically though, it seems this can also be achieved with any full spectrum LED on the market without the extra stressor of UV light. As the scientific studies are lacking here, anecdotal stories and results are all that we can rely on today.

The Claims on UV and Cannabis relation
The claims surrounding UV are widespread enough that it is worth exploring some of them. Of highest interest is the idea that UV-A and UV-B contribute to an increased production of THC in the plant. Science, fundamentally, still hasn’t come to any conclusions on this. Some strains, like OG landrace crosses and cannabis strains from traditionally high-UV areas around the globe have shown some bumps in THC production and secondary cannabinoids. Hemp CBD cultivars, on the other hand, have shown increases in secondary compound production. Overall, today’s indoor, exotic, multiple-cross cultivars have shown no great response to the introduction of UV as a minor stressor. As breeding moves further away from natural outdoor genetics, the added UV can actually cause negative effects for plants that have never been exposed to these types or levels of stressors.

Another claim is that UV-A and UV-B produce more trichomes and more complete heads on the trichomes, creating a frostier looking flower. The jury is still out on this one. Current research into this is in its beginning stages and most of the work so far has been done on hemp. Personally, in my time working with growers around the country, I have heard many stories about better returns on washing hash when UV-A or UV-B was introduced during the grow cycle. Again, there is little hard evidence to these claims though. What this could mean is that we are seeing better structure from our trichomes, just maybe not more of them.

As our research into cannabis continues, we hope to see more data come out of future experiments. Bruce Bugbee has a project underway looking very closely at cannabis’ response to UV-A and UV-B and the UV and Cannabis relation. In a recent interview, shedding some light on his current work, he suggested some of the early research from heavy blues (400-450nm), just short of the UV-A spectrum, were showing similarly beneficial effects.

An additional question we must ask is why are we not seeing more LED light manufacturers adding UV to the fixtures? With UV-A being 50-100x the cost of a full spectrum white or even a deep red LED, the cost for UV is definitely prohibitive. For a manufacturer to include this in every light they sell, it gives pause and begs the question of its validity and value. Especially as we look at commercial facilities who are purchasing hundreds of lights, is there enough evidence (as of the publishing of this article there is not) to support the increased cost?

UV and Cannabis relation and cost impact
Some studies are starting to look into the UV and Cannabis relation and show that UV-A (365nm) and UV-B in small doses or cycles are what really trigger photomorphogenesis within plants, especially cannabis. If these results are proven true, it would mean that UV should not be built-in to LED fixtures unless they have control over it through spectrum tuning or channel control. Interestingly, most LED fixtures on the market today that have UV built-in, have UV-A (395nm), which has yet to be shown any more effective than blue LEDs in the 400-450nm range. As a cautionary note, both UV-B and UV-C must be used with extreme caution around humans and it makes it virtually impossible to have either of these spectrums built-in to an everyday grow light.

Is UV Worthy of All The Hype?
Does this mean we should or shouldn’t invest in UV? Like any other choice you make as a grower, it completely depends on what you are looking to achieve within your grow and with your plants. Depending on your grow style, spending the extra money on a UV fixture may or may not get the result you’re looking for.

Let’s start with our hydroponic growers, which includes anyone with inert media or water based set-ups (since there are many different ways on how to work with coco coir, it is included both here and with the soil media). Hydro/salt growers should have complete control over the nutrients and uptake for their plants. This means they can accomplish a “dialed-in” setup, where ideal uptake and nutrient availability is achieved. Adding UV-A or UV-B to these very low stress environments is probably the most effective application. Anecdotally, we typically see a 3%-5% bump in overall quality (quality = increased terpenes/cannabinoids and/or bag appeal; typically not weight). It is worth emphasizing though that this only applies if you are reaching maximum output from your current setup before adding in UV.

Soil and organic coco coir growers have some secondary things to consider. First and foremost, multiple studies have shown UV-B can degrade organic additions. Bacteria and fungal communities can be impacted and have been shown to actively avoid high UV-B areas. Research also shows that arthropods will be pushed further into the canopy or media to avoid the high UV-B light (more on this later). Secondarily, ask yourself if you’re getting 100% out of your plants already. Is that 3-5% bump from minor stressors going to be worth compromising your additions?

These growers will probably tell you that the color structure and flavor are better than those produced with salts. Will the UV-A and UV-B be that golden key to the production you are already achieving? More times than not the answer to that will likely be no.

UV and Cannabis relation IPM Alert
The Dangerous Side of UV
Finally, let’s touch on UV-C. This wavelength is mostly used in clean-lights and to purify air for indoor areas. It’s a great tool for cleaning and removing contaminants from a grow environment. It can be beneficial as a direct leaf application to control certain types of powdery mildew. It is important to note that the amount of tissue damage from UV-C on leaves and buds is not always worth the help, and long exposure to UV-C or UV-B has been shown to adversely affect plant tissue. It creates an almost burned look on buds and leaves an opening to a secondary invasion from pathogens.

Final Verdict on UV and Cannabis Relation
So, what’s the verdict on the UV and Cannabis relation? It depends! For starters, there has yet to be scientific proof that UV-A adds more value than deep blue (400-450nm) light. If you are growing for terpene or hash production in a hydroponic environment, it may very well be worth experimenting with blue (430nm), UV-A or UV-B to see how it might enhance quality. If you are an organic/soil grower, the addition of UV, given the positive and negative trade offs, may not bring enough value to introduce it into your grow. UV-C should be used in air cleaning devices yet left out of most grow environments, as the impacts on plants and humans alike keeps this in a do-not-use category.

At the end of the day there’s no free lunch and no silver bullet. UV-A, B and C have their advantages and value adds, but they all come at a cost. Just like most things in life, the overall cultivation strategy you employ requires a holistic approach with a defined goal in mind to maximize the outcomes. UV won’t magically change anything and may just be the type of disruption you are trying to avoid. Remember, the devil is truly in the details, especially when it comes to the UV and Cannabis relation.

Greg Selby
Director of Cultivations Sciences, Scynce LED
Specialist in IPM Strategies & Soil Ecology
This is in line with everything I've read so far on the subject......the jury is still out, we need more studies, there are also downsides to adding and using UV....

One thing I'm thinking about is.......how is it going to be measured? Even with a very stable, uniform strain, resin and THC content will still vary a bit from plant to plant. If one plant tests at 18% THC under no added.UV, how do we know what that plant would have tested at if UV were added? Or vice versa? Well, they could test 100, 200 or more plants of the same strain, or cuttings......is anyone doing this, and if so, how? There wouod havev to be a series of controlled studies.
 
Moe.Red

Moe.Red

Staff
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4,590
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Biosynthesis and oxidation of fats is a major goal of Cannabis production. Most good things in Cannabis are lipoxygenase products. ALL desired compounds in Cannabis are derived from electron transport. How does cbg become Thc? How does the nasty children's Tylenol flavor become the delicious "purp" flavor everyone loves?

UV will damage the plant directly through oxidation, damaging DNA and other functions, and many strains are adapted to produce volatile compounds to intercept these damaging rays. Strains adapted to high altitude and exposed locations often respond to intense UV-B by producing volatiles as a way of protecting cellular products from damage, and these volatiles are typically terpenes, thiols, carboxylic acids and phenylpropanoids. In the absence of volatile antioxidant metabolism such as short chain thiols (skunk, garlic, rubber, boxwood,fruit), you see cyanidin glucosides, antioxidant pigments of zero value to the end user.

Photons from light can cause oxidation, though typically they are low energy, and so require sensitisers in the leaf to begin the first stage of oxidation. If no photosensitizer is present, likewise if no non-volatile precursor is present, UV-B will negatively correlate with quality.


Bonus rant:

Growing outdoors isn't going to unlock the full potential of Cannabis on its own. It is very apparent the biggest obstacle for growers is nutrition. That's step one which every grower skips on their journey to becoming a master Ganjier. Next on the list of obstacles modern growers face would be glycosidic bonds trapping flavor active molecules. 3rd would be the total misconception of curing, ignoring the fact that oxidation is the fundamental process of secondary metabolism in Cannabis. Somewhere down the list is 'cides, the fact people think it's okay to spray growing plants. Don't worry about UV until you can feed your plant properly (which obviously eliminates the need to spray shit).

Grow starchy weed, spray it, keep it wet, put it in a fridge, that's what you end up with: nutrient deficient uncured contaminated incompletely metabolized garbage. Now you wanna add UV because that's how most growers roll: Skip the foundation and build a roof. This is what most folks do or aim to do in the Cannabis scene. Earthy = bad nutrition and no cure. Kush should not smell like dirt and peanuts or taste like tobacco. I have seen it thousands of times. Most growers will never smell or taste their strain as intended, as the natural flavor is held back at every turn; through poor nutrition, through incorrect stressors, through bottled contaminants, through attempts to preserve cannabis as if it were lettuce.. It's extremely disheartening that the Cannabis scene has no desire for quality, only for an accepted religion, with revered priests of ignorance, arbitrary qualifiers and a flock of blind sheep to fit in with.

If you want to know why Cannabis isn't like it used to be, this is why. I see growers skip right to buying a cure fridge 'because terps evaporate' or some similar weird concept that requires either zero thought or major mental gymnastics, combined with a total lack of experience with the plant.
Everyone wants to talk "terps" until someone qualified talks back. There are 1000 times more volatiles locked away in glycosides and amino acids than there are floating off a growing bud at harvest and none of the interesting volatiles are on the "Leaflynene" posters. Not on Leafly terp poster? Who cares, it's not accepted dogma, Mendo Dope hasn't rapped about methoxypyrazines, so those aren't cool enough for the cool kids growing the pot these days, not cool like "terps" are.

Maybe my great grandchildren will actually be able to discuss cannabis with their peers. Or will people still be claiming myrcene causes couch lock, claiming that Rick Simpson oil from shit bud cures cancer and claiming fresh freezing is an acceptable production step for a plant dependent on lysis for metabolism?

Go to patreon for the full length extend bonus rant.
Anyone ever tell you that you are a condescending son of a Gun?

Maybe lighten up a bit and jump down off that horse of self proclaimed infinite knowledge and people will engage with you. I think you have some interesting points but I also have zero interest in exchange with you based on the tone of your posts.
 
Harpua88

Harpua88

Supporter
422
93
Someone recommended the Sola-cure UV light to me. Something about hitting the full range, not just one small part of the range and calling it a UV light. Obviously the good people at Sola-cure want us to buy their light......but they do seem to making a jar
Biosynthesis and oxidation of fats is a major goal of Cannabis production. Most good things in Cannabis are lipoxygenase products. ALL desired compounds in Cannabis are derived from electron transport. How does cbg become Thc? How does the nasty children's Tylenol flavor become the delicious "purp" flavor everyone loves?

UV will damage the plant directly through oxidation, damaging DNA and other functions, and many strains are adapted to produce volatile compounds to intercept these damaging rays. Strains adapted to high altitude and exposed locations often respond to intense UV-B by producing volatiles as a way of protecting cellular products from damage, and these volatiles are typically terpenes, thiols, carboxylic acids and phenylpropanoids. In the absence of volatile antioxidant metabolism such as short chain thiols (skunk, garlic, rubber, boxwood,fruit), you see cyanidin glucosides, antioxidant pigments of zero value to the end user.

Photons from light can cause oxidation, though typically they are low energy, and so require sensitisers in the leaf to begin the first stage of oxidation. If no photosensitizer is present, likewise if no non-volatile precursor is present, UV-B will negatively correlate with quality.


Bonus rant:

Growing outdoors isn't going to unlock the full potential of Cannabis on its own. It is very apparent the biggest obstacle for growers is nutrition. That's step one which every grower skips on their journey to becoming a master Ganjier. Next on the list of obstacles modern growers face would be glycosidic bonds trapping flavor active molecules. 3rd would be the total misconception of curing, ignoring the fact that oxidation is the fundamental process of secondary metabolism in Cannabis. Somewhere down the list is 'cides, the fact people think it's okay to spray growing plants. Don't worry about UV until you can feed your plant properly (which obviously eliminates the need to spray shit).

Grow starchy weed, spray it, keep it wet, put it in a fridge, that's what you end up with: nutrient deficient uncured contaminated incompletely metabolized garbage. Now you wanna add UV because that's how most growers roll: Skip the foundation and build a roof. This is what most folks do or aim to do in the Cannabis scene. Earthy = bad nutrition and no cure. Kush should not smell like dirt and peanuts or taste like tobacco. I have seen it thousands of times. Most growers will never smell or taste their strain as intended, as the natural flavor is held back at every turn; through poor nutrition, through incorrect stressors, through bottled contaminants, through attempts to preserve cannabis as if it were lettuce.. It's extremely disheartening that the Cannabis scene has no desire for quality, only for an accepted religion, with revered priests of ignorance, arbitrary qualifiers and a flock of blind sheep to fit in with.

If you want to know why Cannabis isn't like it used to be, this is why. I see growers skip right to buying a cure fridge 'because terps evaporate' or some similar weird concept that requires either zero thought or major mental gymnastics, combined with a total lack of experience with the plant.
Everyone wants to talk "terps" until someone qualified talks back. There are 1000 times more volatiles locked away in glycosides and amino acids than there are floating off a growing bud at harvest and none of the interesting volatiles are on the "Leaflynene" posters. Not on Leafly terp poster? Who cares, it's not accepted dogma, Mendo Dope hasn't rapped about methoxypyrazines, so those aren't cool enough for the cool kids growing the pot these days, not cool like "terps" are.

Maybe my great grandchildren will actually be able to discuss cannabis with their peers. Or will people still be claiming myrcene causes couch lock, claiming that Rick Simpson oil from shit bud cures cancer and claiming fresh freezing is an acceptable production step for a plant dependent on lysis for metabolism?

Go to patreon for the full length extend bonus rant.
It's all good to get into the science of it all, whether everything you're saying is true, and it could very well be...... but one doesn't have to get into molecular botany, floriculture science, whatever you'd call it.......there's science, and there's art. Someone could produce excellent results without knowing the underlying science, or knowing just enough.......My LED lights will work the same whether I learn about ppf of micromoles.....I can harvest when it's perfectly ripe without counting how many trichome heads per square millimeter have turned amber, and I can get an excellent cure without understanding the chemical processes that occur. The science is great........as long as the art isn't lost.
 
Jmcparty

Jmcparty

1
3
I'm still looking for a good uva light bar to toss in my tent with my rspec and cree cobs but dam those are still running over 200.00 and I'm not buying Amazon lights , was looking at black dog but still over 2 grand, so I'm just gonna add to mine that way I can run them in cycles. Heard it's better that way but keep me posted and I'll do same and we'll figure out witch is better together. Keep me posted
Hlg sells UVA light bar that will attach to your rpsec
 
sambapati

sambapati

1,974
263
Biosynthesis and oxidation of fats is a major goal of Cannabis production. Most good things in Cannabis are lipoxygenase products. ALL desired compounds in Cannabis are derived from electron transport. How does cbg become Thc? How does the nasty children's Tylenol flavor become the delicious "purp" flavor everyone loves?

UV will damage the plant directly through oxidation, damaging DNA and other functions, and many strains are adapted to produce volatile compounds to intercept these damaging rays. Strains adapted to high altitude and exposed locations often respond to intense UV-B by producing volatiles as a way of protecting cellular products from damage, and these volatiles are typically terpenes, thiols, carboxylic acids and phenylpropanoids. In the absence of volatile antioxidant metabolism such as short chain thiols (skunk, garlic, rubber, boxwood,fruit), you see cyanidin glucosides, antioxidant pigments of zero value to the end user.

Photons from light can cause oxidation, though typically they are low energy, and so require sensitisers in the leaf to begin the first stage of oxidation. If no photosensitizer is present, likewise if no non-volatile precursor is present, UV-B will negatively correlate with quality.


Bonus rant:

Growing outdoors isn't going to unlock the full potential of Cannabis on its own. It is very apparent the biggest obstacle for growers is nutrition. That's step one which every grower skips on their journey to becoming a master Ganjier. Next on the list of obstacles modern growers face would be glycosidic bonds trapping flavor active molecules. 3rd would be the total misconception of curing, ignoring the fact that oxidation is the fundamental process of secondary metabolism in Cannabis. Somewhere down the list is 'cides, the fact people think it's okay to spray growing plants. Don't worry about UV until you can feed your plant properly (which obviously eliminates the need to spray shit).

Grow starchy weed, spray it, keep it wet, put it in a fridge, that's what you end up with: nutrient deficient uncured contaminated incompletely metabolized garbage. Now you wanna add UV because that's how most growers roll: Skip the foundation and build a roof. This is what most folks do or aim to do in the Cannabis scene. Earthy = bad nutrition and no cure. Kush should not smell like dirt and peanuts or taste like tobacco. I have seen it thousands of times. Most growers will never smell or taste their strain as intended, as the natural flavor is held back at every turn; through poor nutrition, through incorrect stressors, through bottled contaminants, through attempts to preserve cannabis as if it were lettuce.. It's extremely disheartening that the Cannabis scene has no desire for quality, only for an accepted religion, with revered priests of ignorance, arbitrary qualifiers and a flock of blind sheep to fit in with.

If you want to know why Cannabis isn't like it used to be, this is why. I see growers skip right to buying a cure fridge 'because terps evaporate' or some similar weird concept that requires either zero thought or major mental gymnastics, combined with a total lack of experience with the plant.
Everyone wants to talk "terps" until someone qualified talks back. There are 1000 times more volatiles locked away in glycosides and amino acids than there are floating off a growing bud at harvest and none of the interesting volatiles are on the "Leaflynene" posters. Not on Leafly terp poster? Who cares, it's not accepted dogma, Mendo Dope hasn't rapped about methoxypyrazines, so those aren't cool enough for the cool kids growing the pot these days, not cool like "terps" are.

Maybe my great grandchildren will actually be able to discuss cannabis with their peers. Or will people still be claiming myrcene causes couch lock, claiming that Rick Simpson oil from shit bud cures cancer and claiming fresh freezing is an acceptable production step for a plant dependent on lysis for metabolism?

Go to patreon for the full length extend bonus rant.
Good Rant!
 
TSD

TSD

1,949
263
Call me old fashioned, but I still believe it's near impossible to beat that flaming ball of hydrogen in the sky. I've always had a preference for outdoor... scratch that, good, properly grown outdoor... ever since hydro was the hot new thing everyone wanted when I was a teen and I thought they'd all lost their minds and thier taste buds because to me it tasted like chemical soup, made me paranoid and gave me a headache.
I agree with @Moe.Red being condescending gets you nowhere. I'm not a scientist, I don't know all the many terpenes and other things and all thier properties... but I still manage to grow pretty tasty nugs most years that tend to be well recieved by all that try them... with almost no fancy equipment save my low class lights for starting, some good nutes, a preventative spray, some good dirt... and the sun. It's become so much about the commercial side, trying to get you to buy shit to make your plants better, the art of it is getting lost, like @Harpua88 said. The plants tell you what they need if you pay attention. Maybe I'm just a hippie chick at heart. 🤷‍♀️
 
Moe.Red

Moe.Red

Staff
Supporter
4,590
263
Maybe I'm just a hippie chick at heart. 🤷‍♀️
We dig hippie chix!

I had a convo with @Kanashiihawk63 asking her why there are not more women on boards like this. She made some really good points not the least of which is women tend to be more intuitive about plants, less scientific. I’m sure I’m butchering this thought but basically dum boys argue about molecules and efficiency while she just quietly goes about growing beautiful plants while having no desire to know how osmosis works to push ions up the stalk.

There are other examples too like cannagranny who just have a feel for the plant but wouldn’t get into a debate about anything “Jeff” cares to talk about. I’ll bet she outgrows him 2 to 1 tho.

Sometimes we make it harder than it needs to be.
 
TSD

TSD

1,949
263
We dig hippie chix!

I had a convo with @Kanashiihawk63 asking her why there are not more women on boards like this. She made some really good points not the least of which is women tend to be more intuitive about plants, less scientific. I’m sure I’m butchering this thought but basically dum boys argue about molecules and efficiency while she just quietly goes about growing beautiful plants while having no desire to know how osmosis works to push ions up the stalk.

There are other examples too like cannagranny who just have a feel for the plant but wouldn’t get into a debate about anything “Jeff” cares to talk about. I’ll bet she outgrows him 2 to 1 tho.

Sometimes we make it harder than it needs to be.
Totally agree, I'm definitely more of an intuitive grower, but I understand a bit of the science too, probably more so since joining this forum honestly. My mom was a gardener, she made her own super soil before it was called that, didn't measure anything, let her intuition tell her how much, and I've had success doing the same... There really is a such thing as a green thumb. If her house plants were looking sad, she'd give them an aggressive haircut and feed them fish emulsion and they were glorious inside of a few weeks. There's a fine line between knowing the science and using it to your advantage, and trying to completely control a living thing. Sure many products are beneficial, but there is a such thing as too much. When I see someone post all thier goodies and it's like 20 different bottles and a strict schedule, it makes my head spin a little. I get that stuff is necessary in an inert medium... but that's why I do soil.
Not to sound like a feminist man hater or anything, because I'm definitely not, but I think a lot of men follow the old patriarchal beliefs, even subconsciously, that women can't possibly be as good at certain things as men... growing, being a chef, the medical field... which is silly because women have been the growers of food, makers of meals and birthers of babies for millennia. Damn fragile male ego, so easily threatened. 🤣 So maybe that's another reason more women aren't here on the farm, they get sick of having thier skills questioned, having to prove themselves to men yet again, and being made to feel subpar because they happen to have a vagina... because that's a reality of life unfortunately, it was ingrained in society for centuries... I mean we just got the right to vote pretty recently and men are still making laws about our bodies. So maybe most just do thier own thing because they don't want to deal with it and don't need the validation as badly anyway. I'm here to learn personally, and there are plenty of cool guys on here that aren't condescending douchebags. That's the end of my rant lol... and I love men, I'm married to a pretty great one. 😊
 

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