Bud Building with UVB. 20% increase in THC? (I never knew)

[Moshmen]

I just never have enough lol.
I have all 7 strains i have growing right now lol.

It’s an addiction ! Worse the smoking for sure !

 

[SSHZ]

But this is not to say that UV doesn't offer some benefits...........first off, as stated, it hardens up plants and makes them tougher, with thicker leaves and the ability to withstand tougher elements. It also can help in controlling insects and some diseases. Add in its ability to increase terpenes, it maybe worth adding to the grow the last couple of weeks.

On the down side, it can damage plants and thus reduce overall yield if over used.

I bought my UV's thinking it would increase THC, as i heard/read that THC builds as a defense mechanism to defend against the UV on bud surfaces, acting as a diffuser when the light hits it. Science has proved otherwise.

 

[MiGrampa]

But this is not to say that UV doesn't offer some benefits...........first off, as stated, it hardens up plants and makes them tougher, with thicker leaves and the ability to withstand tougher elements. It also can help in controlling insects and some diseases. Add in its ability to increase terpenes, it maybe worth adding to the grow the last couple of weeks.

On the down side, it can damage plants and thus reduce overall yield if over used.

I bought my UV's thinking it would increase THC, as i heard/read that THC builds as a defense mechanism to defend against the UV on bud surfaces, acting as a diffuser when the light hits it. Science has proved otherwise.

@SSHZ
I find it interesting that you said that because it kind of falls in line with my "real world" observations using the very weak UVB light that the Grower's Choice UVR addon bars produce. I have 2 ROI - E720's with the addon bars in one tent. I also have a 630w nanolux in my smaller 5 x 5. Both setups produce great buds. However using same strain clones under both setups, I don't notice any difference once everything has been dried and cured. My theory has been that the grower's choice addon bars don't provide enough UVB to make much of a difference.

Are there newer studies that say differently about UVB and resin production? It was 50 or more yrs ago that it was mentioned in the "Grower's Bible." A lot has changed in the science world since then.

 

[Member Requested Deletion]

The Gelato Dream from Anesia im growing is supposed to be over 30% I figured it wouldnt be that high. Now im going to be known as half toke Dave. One of them is 80 inches today. Gonna be a Monster.

 

[Aqua Man]

Just for reference incase it hasn’t been said a 20% increase to say 20% thc is a whopping 4% and that as @Moe.Red said is not easy to replicate and leaves me wondering what other variables may have been left out

 

[Aqua Man]

UVA also works with the blue spectrum to increase photosynthesis and is the majority of UV we get outdoors. Much like the emerson effect but on the other side of the spectrum. UV is not UV and there is a lot more than meets the eye here.

I dont have the answers but i have went down this rabbit hole more than a few times

 

[SSHZ]

I use the Calif. Lightworks Solarcare UV's...........they are specifically built for a 4 X 4 area, which fits my setup perfectly. You don't need a lot of UV to impact the plants, and less on time with the UVB while more on time with the UVA.

Off the California Lightworks website- "Maryland University researchers found that plants exposed to UVB radiation produced almost 28% more THC than plants grown without intentional UVB exposure." This is the same study everyone quotes and what the light manufacturers rely on when mentioning increases in THC. Unfortunately, the results have never been duplicated, per numerous experts in the field.

Grandpa........I don't think total UV power is the issue here. For the record, my fixtures use 24 watt bulbs. Point is, UV either increases resin production or not- that's what is being debated. I don't get my final product tested these days, so it's impossible for me to judge one way or the other. Lastly, its my opinion that if you grow a healthy product, have good genetics and let them finish well- a small increase in THC probably won't be noticeable.

 

[MiGrampa]

Grandpa........I don't think total UV power is the issue here. For the record, my fixtures use 24 watt bulbs. Point is, UV either increases resin production or not- that's what is being debated. I don't get my final product tested these days, so it's impossible for me to judge one way or the other. Lastly, its my opinion that if you grow a healthy product, have good genetics and let them finish well- a small increase in THC probably won't be noticeable.

That's pretty much what I found out when sampling with UVB and without UVB. I don't have my weed tested at a lab or anything so I don't know if there was any difference between them in THC % etc. If there was, it was not noticeable by smoking it.

Does anybody know if Dr Bugbee has done any studies on this? I'd be interested in what he has to say.

 

[Aqua Man]

That's pretty much what I found out when sampling with UVB and without UVB. I don't have my weed tested at a lab or anything so I don't know if there was any difference between them in THC % etc. If there was, it was not noticeable by smoking it.

Does anybody know if Dr Bugbee has done any studies on this? I'd be interested in what he has to say.

Yes him and migro cover it pretty well

 

[MysticEpipedon]

I have to wonder about that Lydon article. In order to work with weed at that time, it had to be seeds from that farm in Mississippi, which had notoriously bogus weed.

 

[IamN2pot]

I cancled my 310 lamp order from Migro. It wouldn't work running it under my SF4000, not dimmable. To intense at 10-14" over the canopy. Migro suggested I mount it along the side of the SF4000. WHAT??? That would make a real level PPFD map. Order cancled! They should at least make it dimmable for just that reason, IMO. (watch the video) Shane hangs it over 12" above his lamp.
I would like to see more testing of terpenes and flavinoids. If it significantly raises terpenes, that could be worth the investment, but I'd like to see some actual. side by side grow, terpene test results.
Heck, for that matter, I'd love to see some side by side soil vs hydro terpene levels test. I know what the general belief has always been, but where are the test results at to prove or disprove that?

 

[SiamSam]

This is my experience as well.

I have t5 UVB lamps in the giveaway section if that tells you anything.

So you are saying UVB lamps don't work and don't bother..the light I have is also a T5 UVB.... it is pretty easy to get carried away by vendor hype....which is one of the many good reasons why we're here. Impartial testing in real world conditions is our BB Gold (Acapulco) Standard. Heavy sigh....

 

[IamN2pot]

I'm looking for where I read this, it was somewhere to do with the Solacure UVB lamps and the reason they don't use T5's. It had to do with the actual surface area of the bulb. T8's are what are sold by Solacure and Migro and Phillips. As best as I can tell from reading, there could be other possitive effects of using it. Appearently problem molds, PM, and insects hate UV. That in itself may be a good reason to have one.

Impartial testing in real world conditions is our BB Gold (Acapulco) Standard.

I couldn't agree more, and would hasten to add, do the side by side with a brand name T8 Lamp (Migro or Solacure). Then, if you want to compared those results to an Amazon T5 (reptile?) lamp, that would be even better. IDK, thinking out loud. Could one put a T5 on one side of a tent and a T8 on the other side? Then have a lab do a trepene test on flowers from each side? I have read enough at this point to believe that any increase in THC is unlikely at best, but increasing terps or flavinoids?, that seems much more likely, from what I've read.
All that said, we need side by side grows and test results to be sure if it's marketing hype or solid, lab verified and repeatable increases in any results!

Here, is this marketing hype, or can you actually push a 2' UVB lamp up to 40w? @Moe.Red , is that possible?

Because these can be powered with a F20 ballast, you can actually push just as much power through this 2 foot tube as we normally do in a 4 foot tube, although you need to make sure you are at least 3 foot away if you power it with 20 watts. 10-12 watts is normal mode for grow tents. 40 watts for industrial grow applications and greenhouse grows.

Flower Power single bulb 2ft

 

[moe.red]

Yes it does work to add more power, but diminishing returns. You can only excite the phosphors so much, when they are fully excited more power does nothing. Surface area and inverse square law apply here.

Solacure is what I have run. I have burned plants. I have had no impact. I have had darker, denser buds. I have had more purples. Just so many variables.

But the THC spike - never personally achieved it.

For me - I have other variables I am tweaking so for now, UV is not something I am playing with, but still hoping someone out there finds the sweet spot of power, distance, spectrum, and timing that can repeatedly improves some impact of the harvest. To my knowledge, the only results are anecdotal.

 

[Max]

I use the Calif. Lightworks Solarcare UV's...........they are specifically built for a 4 X 4 area, which fits my setup perfectly. You don't need a lot of UV to impact the plants, and less on time with the UVB while more on time with the UVA.

Off the California Lightworks website- "Maryland University researchers found that plants exposed to UVB radiation produced almost 28% more THC than plants grown without intentional UVB exposure." This is the same study everyone quotes and what the light manufacturers rely on when mentioning increases in THC. Unfortunately, the results have never been duplicated, per numerous experts in the field.

Grandpa........I don't think total UV power is the issue here. For the record, my fixtures use 24 watt bulbs. Point is, UV either increases resin production or not- that's what is being debated. I don't get my final product tested these days, so it's impossible for me to judge one way or the other. Lastly, its my opinion that if you grow a healthy product, have good genetics and let them finish well- a small increase in THC probably won't be noticeable.

Spot on man.that’s how I see it aswell.my main focus is keeping a plant as healthy as I can right to the end .I doubt I will ever run them.don’t need to.I already spend enough lol.

 

[SiamSam]

• Our plant expert Matt Fischer says, "The key to success with pulsed UV light is striking the right balance between providing adequate exposure and preventing damage. Careful observation and timely adjustments can help ensure that your plants reap the benefits without any adverse effects."

The Truth About UV Light and Your Plants​

Jessica McKeilDec 03, 2020

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After a recent conversation with a customer about the risk of UV lighting in the grow room, we became intrigued about the full spectrum of UV light. Do plants need UV light to thrive? Is exposure to ultraviolet light harmful? And crucially for us at Happy Hydro, can you protect your eyes from UV rays in the grow room?

Modern grow lights provide a full spectrum of light for your plants, including UV wavelengths that are harmful to human eyes. If you’re interested in protecting yourself from harmful UV-A and UV-B electromagnetic radiation, LED and MH grow room safety glasses—or the HPS and MH variety—are an excellent investment.

During our research on the subject of UV light, we quickly discovered that many sources aren’t as clear-cut as we had hoped. To make the research easier on you, we put together the following guide regarding the truth about UV lights—and how they affect both you and your plants.

If you prefer visual content, we go deep into this topic in our YouTube video here.
Table of Contents
What is UV Light?UV-A:UV-B:UV-C:Best Methods for Giving Plants UV LightWhat Light is Best For Plants?How UV Light Effects Secondary Metabolites in Cannabis PlantsWhat Safety Precautions Do you Need to Take for UV Lights in the Grow Room?

What is UV Light?​

Ultraviolet light, or UV light, is a form of electromagnetic radiation. Light is measured and referred to by its wavelength in nanometers (nm).
The visible spectrum of light falls between 400 nm to 700 nm. Just outside the violet end of the spectrum begins the ultraviolet category, with a wavelength from 10 nm to 400 nm. While the human eye can’t pick up these wavelengths, many other creatures, including plants, use it to survive. When it comes to cannabis (and many vegetables), harnessing someUV light may improve your harvest.
There are three primary types of UV light, including UV-A, UV-B, and UV-C:

UV-A:​

The upper end of the UV spectrum, between 400 nm to 315 nm, is the most prevalent spectrum of UV light on earth. UV-A makes up 98.7 percent of all UV light that reaches us from the sun.

Is UV-A good for plants?​

Most evidence suggests that UV-A exposure isn't tied to DNA damage in plants. This is not a surprising fact, considering that plants are exposed to high levels of low-intensity UV-A in their natural environment. Generally speaking, the UV-A included in most grow room lights won't cause any damage to your harvest, and in the case of cannabis, they might even improve THC and CBD production.

Is UV-A harmful to humans?​

In short diffused doses, there is nothing wrong with a little UV-A light. However, over time or if exposed to intense bursts of UV-A ultraviolet light, it may trigger the development of skin cancer, according to the Skin Cancer Foundation. In particular, researchers link UV-A to melanoma, the deadliest type of skin cancer. Unlike other forms of UV light, UV-A isn’t filtered-out by glass windows. This is what leads to faded curtains and aging artwork. It is also the light spectrum responsible for wrinkles and age spots.

UV-B:​

The second most common UV wavelength to reach the earth from the sun is UV-B. Its electromagnetic wavelengths range from 314 to 280 nm. UV-B triggers oxygen creation and the regeneration of the ozone layer. It makes up the remaining 1.3 percent of UV light reaching the earth’s surface.

Image sourced from Adobe

Is UV-B good for plants?​

In the right dose, introducing a small amount of UV-B ultraviolet light to your indoor plants can be a good thing. This light spectrum encourages plants to produce their own natural sunscreen. These “sunscreens” vary from one species to another—in the case of cannabis, the development of trichomes, terpenes, and colors will be affected. The UV-B spectrum also offers a bit of natural protection against fungal infections and unwanted pests.

Is UV-B harmful to humans?​

Humans have a love-hate relationship with this middle spectrum of UV light. On one hand, UVB light triggers Vitamin D production. On the other hand, it can damage the skin, and will eventually cause skin cancer if left unchecked. Us humans require UV-B, but we also need to take precautions against too much of it. Most available sunscreens include protection against harmful UV-B rays—grow room glasses serve the same purpose for your eyes.
"Ultraviolet (UV) light exposure leads to the development of a denser cuticle layer in plants. This protective barrier reduces water loss through evaporation, ultimately enhancing the plant's water efficiency."

UV-C:​

UV-C is not present in the UV light that reaches the earth’s surface. While UV-C light is now artificially made, the ozone layer completely absorbs this wavelength, meaning that no UV-C light penetrates through the Earth's atmosphere. It ranges in wavelength from 280 to 0 nm.

Image sourced from Adobe

Is UV-C good for plants?​

This is where the truth about UV light in the grow room gets a bit confusing. Out in the great outdoors, plants are not naturally exposed to UV-C lighting, because it doesn’t permeate through the ozone layer. They don’t need it to grow, and it can be one of the most damaging wavelengths of light to expose your plants too. Many growers don't realize that UV-C does damage to the plant's DNA.
But, with that said, UV-C lighting wands are often sold as a hand-held tool designed to sanitize the workroom from microorganisms. These wands borrow from UV-C technology used to sterilize water in the backcountry. Ultimately, UV-C will kill everything with too much exposure, including your plants. If you do decide to use a UV-C wand in your grow room, cover up and protect yourself and your plants from excessive exposure. Your plants certainly do not need UV-C to grow, and your grow lights don't produce it.

Is UV-C harmful to humans?​

Us earthlings take our ozone layer for granted. Few realize that without the protection of the invisible atmospheric barrier, we would face a constant barrage of dangerous UV-C ultraviolet light. This spectrum of light is hazardous to humans, even with limited short-term exposure. If intense enough, UV-C light can cause lesions, burns, or redness. Over the long term, it speeds up the visible signs of aging and also leads to skin cancers.

Best Methods for Giving Plants UV Light​

When it comes to optimizing plant growth and health, the right approach to UV light exposure can make all the difference.

In this section of our blog, we'll explore the advantages of the Pulse UV Method over the Steady State UV Method and discuss how to implement it effectively to enhance your plants' well-being.

Pulsed vs. Steady State UV Light: A Comparison​

The Pulse UV Method involves administering shorter, intermittent bursts of UV light, while the Steady State UV Method maintains a continuous flow of UV light.
The general consensus is that pulsed UV light can be more beneficial for plants, as constant exposure to UV light may cause harm or trigger an excessive UV response that hinders the plant's ability to absorb the rays.

Implementing the Pulse UV Method for Optimal Plant Health​

To make the most of the Pulse UV Method, it is recommended to apply it for an hour, a couple of times during the light period.
While doing so, it is essential to closely monitor your plants for any signs of damage or burning, and adjust the exposure accordingly.
Our plant expert Matt Fischer says, "The key to success with pulsed UV light is striking the right balance between providing adequate exposure and preventing damage. Careful observation and timely adjustments can help ensure that your plants reap the benefits without any adverse effects."

 

[IamN2pot]

Hello MIGRO!
As you've read in my OP, I ordered a 310 UVB lamp from Migro and then promptly canceled the order when I realized that the 20%+ increase in THC claimed in the study had never been duplicated. All went well with canceling, ...I thought. The charge on my CC was reversed, but then Monday evening the UPS truck left me a surprise, from MIGRO. WHAT??? So, I emailed Migro to tell them I needed a return shipping label. To my complete suprise their response was basically, 'our fault, keep the light'. OOOOKKKKK, if you insist. Thank you MIGRO.
If you want to follow the grow with this UVB, I still have about 10 days or so (day 62 today) before any harvesting in my grow journal, here. https://budbuilders.org/threads/ori...entic-genetics-seed-company-grow-journal.161/

And as for the lamp unboxing, testing and mounting it under my SF4000, here you go. I have its timer set for 1.5 hours during mid-day in the tent. It's mounted so the bottom of the bulb is 18" above the top of the colas. (Oh, and my Anesia seeds are due to be delivered today) ALL IS GOOD!