GrumpyOlddude
Active Member
Has anyone used 390nm-430nm violet LED’s and if so to what effect? Also what ratio did you use them with COB’s.
390-430nm Violet LED’s
- Thread starter GrumpyOlddude
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brazzik25
Well-Known Member
[QUOTE = "GrumpyOlddude, сообщение: 15994708, участник: 919590"]
Кто-нибудь использовал фиолетовые светодиоды 390-430 нм и если да, то с какой целью? Также в каком соотношении вы использовали их с COB.
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www.valoya.com
Кто-нибудь использовал фиолетовые светодиоды 390-430 нм и если да, то с какой целью? Также в каком соотношении вы использовали их с COB.
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Is UV Light Important for Cannabis?
UVA light has been shown to increase secondary metabolite activity in many plants, and this is also the case with cannabis. The most important secondary metabolites from a cannabis grower’s …
www.valoya.com
GrumpyOlddude
Active Member
Bump. That Valoya article was not helpful
race winslow
Well-Known Member
TheWholeTruth
Well-Known Member
In that range are they even actually regarded as true uv or just show pieces on the lights and just a mind marketing trick. I know real uv chips are very expensive and can burn out quick.
race winslow
Well-Known Member
TheWholeTruth
Well-Known Member
Looks like you definitely known what your doing. Very cool set up too. How have you got on with your uv set up, notice any differences. Mind sharing what sort of size your working with there under the lights. Thats the first time I've seen tubes that big employed in such a set up. Id be interested in how you use them and if you see much detrimental effects on the plants. Its really interesting to see someone push the boundaries a little and think outside the box. Appreciate the pictures.
race winslow
Well-Known Member
Hi,
So, here's a link to the website that sells the bulbs and fixture. I have the 48" Flower Power set-up.
Kit: Two Flower Power bulbs + 2 fixtures (4 ft) + Timer (solacure.com)
Also, here is a link to some discussion about UV and when and how long to use use it during your grow. You'll find that there are different schools of thought on the subject. For me, I run mine for 15 minutes on the hour. That's a total of 3 hours for every 12 hours of flowering. I have them about 12 inches from the tops of my plants and I'm not seeing any damage. There's no leaf curling up or turning brown or rusty looking.
Flower Power F40 (4 foot) (solacure.com)
I'm with you on the "Digital UV/IR vs Gas based bulbs (analog). They cost a lot and the spectrums are not typically as broad as the analog type.
This is my first grow with this set up. So far, I'm quite happy with it. The buds are about 36 days in. I probably have another 3-4 weeks to go.
As I mentioned, there is do damage to the plant and the buds seem ahead of schedule and full of frost and terpenes.
I have these attached to a Timber Fatty 900 watt fixture.
I wanted the set-up to mimic an HPS so I configured the fixture with 3-1750k, 3-3k &3-3500k bulbs. That combination equals a color temp of about 2750K. So, between the fixture color temp and the UV I'm getting a more HPS, MH type of light. So far, so good.
Grow Lights Australia
Well-Known Member
Yes, but not with COBs. The effect was a higher percentage of cannabinoids than those grown under UVB. This is our third test on the subject (UVA/Violet vs UVB): https://rollitup.org/t/latest-uva-vs-uvb-cannabinoid-test-results.1052083/
race winslow
Well-Known Member
Any speculation on the potential impact of COBs? I use Citizens Vero's. I have 5-1750k, 2-3k and 2-4k. Average color temp equals approximately 2530k.
Grow Lights Australia
Well-Known Member
Well LEDs are LEDs so it depends on the original spectrum, but almost no COBs have UV or near-UV to begin with except Yuji (that I know of – if anyone knows any others, please tell!), so they would benefit just like any other mid-power LED. There's no voodoo with COBs, they are just LEDs, even though they run hotter and are a little less efficient than mid-powers and others that spread their diodes.
Do you know what model COBs you are using? Are you sayig you use both Citizens and Veros (which are made by Bridgelux)? Sorry I'm just trying to figure out exactly what you have already.
Also, I agree with you that fluoro is the chepeast and best form of UVB on the market at the moment, but the question is whether you can equal or beat UVB with UVA and near-UV, which we believe is possible based on our tests. The trick may be the amount of time you expose your plants, as UVB breaks down cannabinoids faster than UVA, so excessive exposure can actually destroy cannabinoids almost as fast as the plant produces them in relation to being exposed to UVB in the first place. With UVA and near-UV, you can expose the plants for longer without breaking down cannabinoids as fast, so this seem to be the secret to why it works so well. LEDs can produce UVA in the higher ranges much more efficiently than fluoro, and while their lifespan is not as long as typipcal LEDS (20,000-30,000 hours vs 50,000), they are getting better all the time. UVB diodes, on the other hand, are expensive to produce (they need ceramic packaging vs plastic) and do not last as long.
So for UVB, I say fluoro, but for UVA above 365nm (especially around 395-405nm) it looks like LED is still the answer.
430nm is a different story, as it coincides with the typical Chlorophyl A peak at the same wavelength and is not typically associated with producing secondary metabolites to the same effect as UV – although blue light is also know to help with production of secondary meabolites. 430 helps with Pfr abserption.
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race winslow
Well-Known Member
Hi,
Thanks for responding. Yes, I do understand that COBS are LED's. These are the COB's that I have in my light. Vero29 Generation 7 COB LED's.
I brought up COB's because in one of your posts you responded to this question:
"Has anyone used 390nm-430nm violet LED’s and if so to what effect? Also what ratio did you use them with COB’s."
Your Response:
Yes, but not with COBs. The effect was a higher percentage of cannabinoids than those grown under UVB. This is our third test on the subject (UVA/Violet vs UVB): https://rollitup.org/t/latest-uva-vs-uvb-cannabinoid-test-results.1052083/
Therefore I asked my question:
Any speculation on the potential impact of COBs? I use Citizens Vero's. I have 5-1750k, 2-3k and 2-4k. Average color temp equals approximately 2530k
Your Response:
Well LEDs are LEDs so it depends on the original spectrum, but almost no COBs have UV or near-UV to begin with except Yuji (that I know of – if anyone knows any others, please tell!), so they would benefit just like any other mid-power LED. There's no voodoo with COBs, they are just LEDs, even though they run hotter and are a little less efficient than mid-powers and others that spread their diodes.
I didn't suggest that:
"There was voodoo with COBs"
Specifically, my question was more about the color temp spectrums that I'm using and would that have an impact on the results. I don't doubt the results and observations that your tests have generated. However, there are many variables that need to be controlled for before a blanket statement can be made that UVB is not good for cannabis plants. There is still much literature out there that maintains that UVB is beneficial. Among some of the control points that need to be accounted for include:
Genetics - the origin of the plants have an influence. I.e. are they equatorial/high elevation strains which are genetically predisposed to handling higher levels of UV?
Environmental factors - how stable/consistent is the growing environment? Is the temperature/humidity consistent. Is there a constant use and ratio of CO2?
Nutrients - Is there variability in the nutrients? Is there a consistent formulation and application of them?
Lighting - How close are the lights to the plants? Is it optimal for the strain? Is the color temp impacting UV?
Harvesting - When are the plants harvested? Are the trichome clear, milky or showing significant amber?
In my test grow set-up I'm using a Timber Fatty configured with Vero29 Generation 7 COB LED's. It has 5-1750k, 2-3k and 2-4k. Average color temp equals approximately 2530k. Additionally, I have attached two Solacure 48" Grow Power fixtures and bulbs. They are spread out approximately 18" from each other and give me full coverage of the canopy. My goal for this test grow is to determine if the plants exceed the ceiling the breeders have stated for each strain. I will be doing so by using a commercial testing facility that most of the growers and dispensaries in my area use. As you alluded, testing isn't cheap.
I'm doing this all out my own pocket. I have not received any financial gain or support from any product that I may mention. This is for my own information as I try to keep upping my game as grower.
There is a lot of conflicting information on the internet about UV. You have provided information that suggests that UVB is bad for THC production. SolarCure suggests the opposite and has their own research information to back up their claims.
Cannabis (solacure.com)
Who's right?....I honestly don't know and the information presented by both side of this question sounds convincing. How does one decide?
I want to be growing my bud under the best conditions and using the most effective lighting, nutrients, techniques and etc. that I can.
I don't care about brand names, light types and so forth. Just looking for guidance and truth to help me reach my goals of growing the best buds that I can.
Thanks,
brazzik25
Well-Known Member
race winslow
Well-Known Member
Thanks! An excellent article and it reinforces my decision to use 5 -1750K cobs in my light configuration. I was trying to duplicate an HPS color profile. I've grown under LED, HPS and CmH. Up until I got the Timber Fatty, my best results were under HPS. I always achieved better yield, terpene/thc performance and bud density. I've surpassed that under the Fatty that I had configured similarly to what this article suggests is optimal.
Grow Lights Australia
Well-Known Member
I'm sorry if my response sounded a bit rude. I didn't mean for it to be, but I was unsure of what it was that you wanted to know. The OP asked the question and I responded that we had done some trials, but that we had not used COBs. I made that point merely to address the subject title. That was all.I'm doing this all out my own pocket. I have not received any financial gain or support from any product that I may mention. This is for my own information as I try to keep upping my game as grower.
There is a lot of conflicting information on the internet about UV. You have provided information that suggests that UVB is bad for THC production. SolarCure suggests the opposite and has their own research information to back up their claims.
Cannabis (solacure.com)
Who's right?....I honestly don't know and the information presented by both side of this question sounds convincing. How does one decide?
I want to be growing my bud under the best conditions and using the most effective lighting, nutrients, techniques and etc. that I can.
I don't care about brand names, light types and so forth. Just looking for guidance and truth to help me reach my goals of growing the best buds that I can.
Thanks,
I would be fascinated to see the results of your tests and I applaud you not only for your willingness to spend your own money in the name of science (yes, testing is not cheap!) but on your excellent lighting set-up. Your plants look beautiful and healthy and you have obviously put a lot of time and thought into your set-up.
However, I would like to clear up a couple of things before we go on.
The first is, I am not saying "UVB is bad". What I am saying is UVB degrades canabinoids by accelerating the oxidisation process. This is well-known. While UVB does increase cannabinoids by stressing the plant into producing secondary metabolites, it also breaks them down at the same time. It is the net effect we are interested in.
In other words, how much THC/CBD etc is left over after exposing your plants to UVB considering that UVB helps to increase cannabinoids but also breaks them down at the same time? Is there an optimum amount of time for exposing plants to UVB so as to increase cannabinoid production but to reduce oxidisation? And can the same effect be produced by exposing plants to UVA and near-UV, which is both cheaper (in terms of LED production), less energy consuming, and less dangerous for humans to work under?
That is really the purpose of our tests.
The other point which led to my initial confusion is that colour temperature is not an ideal metric of light output. There are many ways to produce the same kelvin temperature in a light, but the CRI and spectral weavelengths can vary enormously.
If the average colour temp of your lights is around 2500K, then why not just use 2500K COBs alround? Because there are other considerations.
The Veros you are using come in different configurations. The 1750K version is CRI80, however the 3000K versions come in CRI 80, 90, 93, 97 and all of these COBs will have different spectra typically ranging from narrow spread (CRI80) to wide spread (CRI97). There is a big difference in the amount of Far Red in each of these, and Far Red is very important to yield. (There is also a big difference in efficiencies, more of which below.)
This ^ is not a Bridgelux spectrum chart but it shows how much of a difference there is in the amount of Red and Far Red between the CRI80 and CRI93 versions of these 3000K Cree LEDs. Not all colours are created equal when it comes to lighting plants.
Here is the Vero 29 graph for your 1750K COBs (below), of which there is only one version (CRI80). It is a good choice for supplementing broad-spectrum Red and Far Red as it produces almost 2/3 of its light in this region.
What this proves is that you need to look beyond kelvin temperatures and concentrate more on actual spectrum. But you also need to look at LED efficiency, as higher CRI LEDs tend to have lower efficiencies due to the phosphor coating conversion of blue light (base LED emission, or "blue pump" die) to other colours (green and red).
Why is Far Red so important? Even the study posted above hypothesizes that the increased Far Red light in the DE HPS fixture may have accounted for some (or all) of the yield increase, negating some of the initial observations about blue light.
We also can't ignore other scientific tests that have shown an increase in blue light can also lead to an increase in THC production. My main concern with the above study is that they used a variety of hemp or CBD-rich cannabis instead of a THC-rich version (0.3% THC is an industrial hemp classification), so we will never know from that study how blue light really affects THC production – which is the ultimate aim of many growers.
I'm sorry for jacking this thread but I think you are doing a great job and will find what works for you. If you can share your resuls with the rest of the community, even better!
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race winslow
Well-Known Member
No worries, it's all good.
I appreciate the time and thought that you put into your responses. It is quite clear to me that you have a much more comprehensive understanding of this topic.
I realize that you did not say bad. However, one could infer that UVB may not be the best way to go. As you indicated, the application of UVB influences the results. Personally, I give the plants 3 hours per day. I run the UV for 15 minutes on the hour. So, I'm cycling. There is also the school of thought that longer duration doses are the way to go. Your results seem to not support that notion and at this point I tend to agree. Regardless of whether one is cycling or steady dosing, proximity to the canopy is not to be overlooked. I'm measuring leaf temperature to keep things honest.
Regarding the configuration of my COB fixture; I had limited choices from which to choose. As I indicated, my goal was to try and emulate an HPS/MH type of spectrum. In addition, as this is an all purpose light, I felt that I needed sufficient blue for vegetative growth. Hence, the 4k's. I used the 3k's to try and get close to the 500-580 spectrum for sufficient yellow and green representation and additional red support. Finally, I went heavy on the 1750K's to try and have a wide spread of red/far red light. Using all 2500k's would not accomplish that and they weren't available to me. Overall, I think the light has performed the way I had hoped. I recognize that it doesn't have the efficiency of most high quality strips or boards. However, while better efficiency would be nice, it wasn't my primary objective. I've used numerous led lights over the years and that's what I started growing with indoors. I finally got so fed up with LED that I started using a used 600 watt HPS that a friend given me. I put in a new Eye Hortilux Super HPS and kept everything else the same as far as nutrients and etc. were concerned. I immediately got the best results that I'd had in 6 years of indoor growing. Those results I felt were related to the color spectrum. That's when I turned to COB's. Many led lights claim to replace a 1000 watt DE or HPS and they may do so from an efficiency standpoint. However, few seem to replicate the aesthetics that DE and HPS provide (i.e) terpene production. trichome density and overall flower bulk. I feel like I'm getting that now. I added the UV to try and cover the 280 - 400 spectrum in an attempt to further potency and further bolster aesthetic appeal. Time will tell if I'm track to meeting my goals.
Here are the cob spectrums that I had available to me:
In closing, I appreciate the knowledge that you supply here and that of fellow growers that share their insights. Hopefully, it's all leading to a higher plain.
Grow Lights Australia
Well-Known Member
The problem with the horticultural LED industry is there is a lot of bullshit out there, such as claims that 200W fixtures can replace 1000W of HID etc.
We have a lot of experience replacing HPS with LED and I can tell you the secret to HPS yield is threefold:
1. Cannabis has been selectively bred to perform best under HPS for decades. Because most indoor growers and breeders used HPS throughout the 90s, noughties and onwards, the best-performing plants under that spectrum where bred from, which means that even to this day some of the old-school strains perform really well under HPS.
2. HPS has a lot more Far Red than typical CRI80 3000K LEDs used by many producers, and very little blue – both of which impact growth and flowering yields. In fact, HPS can cause an optimal amount of stretch in a plant that then fills in whereas some LEDs can produce compact growth that shadows undergrowth preventing it from developing. An optimal amount of stretch is often desired in some strains to get the best yields, as it facilitates better light penetration and actually increases canopy volume (think of your canopy in terms of 3D – Height x Width x Length – instead of 2D – Width x Length).
3. Metabolic warmth can accelerate growth. If a growroom is cold, adding a HPS for extra warmth can have benefits over LED – but only if the growroom is below optimal temperature. In situations where temperatures are already ideal (30+C), the added heat of a HPS can be detrimental.
Having said that, the right LED will still equal or outperform HPS with much less energy and nearly always produces better quality flowers.
We have a lot of experience replacing HPS with LED and I can tell you the secret to HPS yield is threefold:
1. Cannabis has been selectively bred to perform best under HPS for decades. Because most indoor growers and breeders used HPS throughout the 90s, noughties and onwards, the best-performing plants under that spectrum where bred from, which means that even to this day some of the old-school strains perform really well under HPS.
2. HPS has a lot more Far Red than typical CRI80 3000K LEDs used by many producers, and very little blue – both of which impact growth and flowering yields. In fact, HPS can cause an optimal amount of stretch in a plant that then fills in whereas some LEDs can produce compact growth that shadows undergrowth preventing it from developing. An optimal amount of stretch is often desired in some strains to get the best yields, as it facilitates better light penetration and actually increases canopy volume (think of your canopy in terms of 3D – Height x Width x Length – instead of 2D – Width x Length).
3. Metabolic warmth can accelerate growth. If a growroom is cold, adding a HPS for extra warmth can have benefits over LED – but only if the growroom is below optimal temperature. In situations where temperatures are already ideal (30+C), the added heat of a HPS can be detrimental.
Having said that, the right LED will still equal or outperform HPS with much less energy and nearly always produces better quality flowers.
race winslow
Well-Known Member
That's the trick getting the right LED grow light....
I'm all ears if you have a suggestion for me.
I have used an HLG R Spec Scorpion
horticulturelightinggroup.com
I'm willing to try something new.
I'm all ears if you have a suggestion for me.
I have used an HLG R Spec Scorpion
HLG Scorpion® Rspec®
HLG Scorpion Rspec is designed for grows with low ceiling heights or vertical racks. HLG Scorpion Rspec uses 6x Rspec 288 Quantum Boards for an even light spread at just 12" from the canopy. QB 288 uses Samsung's latest LM301H and Deep Red LED 660nm. Commercial Indoor Horticulture LED grow light
horticulturelightinggroup.com
I'm willing to try something new.
Grow Lights Australia
Well-Known Member
Hey mate, well I didn't post here to sell you a light! But I can tell you the R-Specs have negligible Far Red in them, which is where we believe the real yields and shorter flowering times come in. In that respect I think the COBs you have now fit the bill. Even though they are less efficient, the 1750K COBs have a good amount of Far Red.That's the trick getting the right LED grow light....
I'm all ears if you have a suggestion for me.
I have used an HLG R Spec Scorpion
HLG Scorpion® Rspec®
HLG Scorpion Rspec is designed for grows with low ceiling heights or vertical racks. HLG Scorpion Rspec uses 6x Rspec 288 Quantum Boards for an even light spread at just 12" from the canopy. QB 288 uses Samsung's latest LM301H and Deep Red LED 660nm. Commercial Indoor Horticulture LED grow light
I'm willing to try something new.
There are two schools of thought here: the first is that efficiency beats spectrum – which is true to an extent. More photons (up to a point) will drive more photosynthesis.
The second school of thought is that efficiency + spectrum beats efficiency alone - which is where we fit in. We believe that although photon count is the biggest driver of photosynthesis, there are limits, and that the secret to better yields is to get both efficiency and targetted spectrum up to optimum levels. That's why we produce an LED panel that tests at 3.0 umol/j but also has a "true" full spectrum all the way from 395nm-780+nm, including almost 10% Far Red and 5% UV and near-UV. We know this works, because it is beating almost everything else we've trialled against it.
So, I'm not saying buy our lights, but I am saying that if you want the best LEDs, then look for both efficiency and spectrum – and don't be fooled by the "full spectrum" mantra that many other companies tout, because they are not "true" full spectrum. They either lack light from 400-450nm, or over 700nm, or both.
It is now commonly accepted that Far Red over 700nm not only drives photosynthesis but is more efficient than just about any other spectrum, especially when combined with red and deep red around 620-660nm (Emerson Effect), because it penetrates deeper into the leaf and is absorbed by more chloroplasts under the surface. Green light also penetrates, but Far Red is less energy intensive to produce and has a synergistic effect with red light that increases photosynthetic efficiency.
Don't get me wrong. I'm not rubbishing the other lights. All I'm saying is that if you want the best out of them, you need to add supplementary Far Red and blue/near-UV from <400-430nm. You will notice the difference.
race winslow
Well-Known Member
I don't think that I ever indicated that I thought you were trying to sell me a light mate!!
Don't get me wrong. I'm not rubbishing the other lights. All I'm saying is that if you want the best out of them, you need to add supplementary Far Red and blue/near-UV from <400-430nm. You will notice the difference.
Yes, that's what we've been discussing.
Unless I'm mistaken, the 1750k cobs that I'm using do supply far red. Also, I'm already 4k blue and UVA/b from 285 on up.
Your responses had gotten me more interested in your lights. So if you have a model that you'd recommend I'd be interested in seeing if they make sense for me.
If not, okay then...
Don't get me wrong. I'm not rubbishing the other lights. All I'm saying is that if you want the best out of them, you need to add supplementary Far Red and blue/near-UV from <400-430nm. You will notice the difference.
Yes, that's what we've been discussing.
Unless I'm mistaken, the 1750k cobs that I'm using do supply far red. Also, I'm already 4k blue and UVA/b from 285 on up.
Your responses had gotten me more interested in your lights. So if you have a model that you'd recommend I'd be interested in seeing if they make sense for me.
If not, okay then...