Is UV supp really needed w LEDs???

MIGrampaUSA · Dec 16, 2021

Backyard_Boogie said:
Can someone on here tell me the suggested amount of hours that UV reptile bulbs should be running during veg? In my 18 hour cycle Im running the bulbs for 30min at a time spread out 5 times through the cycle. So in total 2.5 hours for an 18hour cycle. Is this too much? Too little? any info would be helpful thanks.

I can tell you what California Lightworks UVB light directions say. It's what I bought. Quality in my eyes is sub par so stick to the reptile lights. According to California Lightworks, UVB works best if used mid flower through to harvest. They recommend starting at 1 hr on in the middle of the light cycle and then increasing the time by 1 hr every week. This is what I've done.

However, I've known of others using them most of the grow but they also start slow and build up the time. I've been told if you do it that way you may also have to dim your grow lights a bit otherwise the UVB could be too strong.

Observationist · Dec 16, 2021

tobh said:
I would say wait till flower. Not sure what the end goal is running it in veg is all I'm saying. If the goal is to produce more terpenes and trichomes, a plant isn't primarily focused on those things in veg.

Oh yea, you don’t use UV spectrum in veg lol

Backyard_Boogie · Dec 16, 2021

Observationist said:
Oh yea, you don’t use UV spectrum in veg lol

OK. This is good to know it will save me on electricity costs. During the 12/12 how many hours of runtime per cycle?

MIGrampaUSA · Dec 16, 2021

Backyard_Boogie said:
OK. This is good to know it will save me on electricity costs. During the 12/12 how many hours of runtime per cycle?

Start at an hour in the middle of your daylight cycle. Increase that time by an hour every seven days. Depending on exactly when you start and how long it flowers ... 4 hrs and in some case up to 6 hrs. You don't need to run it the full 12/12. For example., I run my lights 9:30a - 9:30p. Mid day would be 3:30pm. The first week I ran it between 3pm and 4pm. The second week between 2:30pm and 4:30pm. And so on. I'm at 4 hrs on now. I expect to harvest over Christmas. At that time, my uvb will be up to 5hrs time.

This is how I did it. Others might have approached it differently. Most people will tell you to start slow and build up the time as you go.

Backyard_Boogie · Dec 16, 2021

MIGrampaUSA said:
Start at an hour in the middle of your daylight cycle. Increase that time by an hour every seven days. Depending on exactly when you start and how long it flowers ... 4 hrs and in some case up to 6 hrs. You don't need to run it the full 12/12. For example., I run my lights 9:30a - 9:30p. Mid day would be 3:30pm. The first week I ran it between 3pm and 4pm. The second week between 2:30pm and 4:30pm. And so on. I'm at 4 hrs on now. I expect to harvest over Christmas. At that time, my uvb will be up to 5hrs time.

This is how I did it. Others might have approached it differently. Most people will tell you to start slow and build up the time as you go.

OK got it. And also sorry fellas for asking the same question multiple times for whatever reason I didn't refresh my browser to see that you already answered this a little bit ago. I will go in my garage and shut off the UV now. I will wait until I am half way info flower then I will start with 1 hour a day in the middle of the lights on cycle. Each week I will add an hour until I hit a max around 4 like you. Thanks.

Backyard_Boogie · Dec 16, 2021

Bellbottomgenes said:

This was very informative thanks.

Kevuk · Dec 16, 2021

The reptile bulbs are much milder than the tubes. I’m not sure how effective they are for plants?

My problem is a quantum board in a 4x2. If I hang a tube above it most of the light will be blocked by my led.

PizzaBob · Dec 17, 2021

Kevuk said:
The reptile bulbs are much milder than the tubes. I’m not sure how effective they are for plants?

My problem is a quantum board in a 4x2. If I hang a tube above it most of the light will be blocked by my led.

Either (2) 2’ at the ends at same height or just one 4’ on either side same height.
I have more lights but basically I have at same height and I’m getting good coverage. I got 2 runs of 2 between lights.

PizzaBob · Dec 17, 2021

MIGrampaUSA said:
Start at an hour in the middle of your daylight cycle. Increase that time by an hour every seven days. Depending on exactly when you start and how long it flowers ... 4 hrs and in some case up to 6 hrs. You don't need to run it the full 12/12. For example., I run my lights 9:30a - 9:30p. Mid day would be 3:30pm. The first week I ran it between 3pm and 4pm. The second week between 2:30pm and 4:30pm. And so on. I'm at 4 hrs on now. I expect to harvest over Christmas. At that time, my uvb will be up to 5hrs time.

This is how I did it. Others might have approached it differently. Most people will tell you to start slow and build up the time as you go.

What do you have running and size of room. I’m gonna ramp this up big time based on what your saying. At about 45 minutes a day now.

MIGrampaUSA · Dec 17, 2021

PizzaBob said:
What do you have running and size of room. I’m gonna ramp this up big time based on what your saying. At about 45 minutes a day now.

I have this set up with a Growers Choice ROI - E720 running at 100%. It's in a 5 x 5 x 80" tent. Two 24w California Lightwork's Solar UVB hang through the space of the bar light. This grow will be wrapped up in a couple of weeks.

I bought two 150w Reptile lights to run in my 6.5 x 6.5 x 80" tent. These have not been used yet as those plants are still in veg. Still to be determined ... I might add one more to that tent.

PizzaBob · Dec 17, 2021

MIGrampaUSA said:
I have this set up with a Growers Choice ROI - E720 running at 100%. It's in a 5 x 5 x 80" tent. Two 24w California Lightwork's Solar UVB hang through the space of the bar light. This grow will be wrapped up in a couple of weeks.

I bought two 150w Reptile lights to run in my 6.5 x 6.5 x 80" tent. These have not been used yet as those plants are still in veg. Still to be determined ... I might add one more to that tent.

Nice interesting to see how it compares.

ritoMox · Sep 1, 2022

tobh said:
I would say wait till flower. Not sure what the end goal is running it in veg is all I'm saying. If the goal is to produce more terpenes and trichomes, a plant isn't primarily focused on those things in veg.

Maybe generations of indoor-growing has suppressed beneficial genes, and running uv from seed to finish based on the daytime/yearly Sun uv index would wake those genes up. For example, the uv index shows the uv starting out low in the morning and increasing to mid-day and then dropping off till nightfall. So some kind of uv light controller to replicate that increase/decrease of uv might be the best way to go about it(?).
"As would be expected, the highest amount of solar intensity occurs on the globe right where the sun is overhead and as the angle of the sun lowers, the solar intensity declines". Link
"Time of Day - UV exposure is highest between 10 a.m. and 4 p.m. because the sun’s rays don’t have to travel as far during this window, making them more powerful". Link

Link
Link

Peat_Phreak · Sep 1, 2022

https://www.frontiersin.org/article...econdary metabolite composition. Introduction

The present study from 2021 suggests that using UV radiation as a production tool did not lead to any commercially relevant benefits to cannabis yield or inflorescence secondary metabolite composition.

It actually decreased terpenes and THC.

ritoMox · Sep 1, 2022

Peat_Phreak said:
https://www.frontiersin.org/articles/10.3389/fpls.2021.725078/full#:~:text=The present study suggests that using UV radiation,cannabis yield or inflorescence secondary metabolite composition. Introduction

The present study from 2021 suggests that using UV radiation as a production tool did not lead to any commercially relevant benefits to cannabis yield or inflorescence secondary metabolite composition.

It actually decreased terpenes and THC.

Yeah, reading through that link really just makes me think that it's a genetic/s issue. Many generations of growing indoors with no uv may have suppressed the genes that are normally active outdoors. Exposing those supressed lines to uv is bound to cause some problems. I think that their study should have taken place over many generations to see if there was any improvement. 2¢

testiclees · Sep 1, 2022

Ive been using this rig for a couple months.

N1ghtL1ght · Sep 1, 2022

ritoMox said:
Yeah, reading through that link really just makes me think that it's a genetic/s issue.

Yeah, ignore that BS study, it's rigged, twice.

Genetics used:
‘Low Tide’ (LT) and ‘Breaking Wave’ (BW)
both high-CBD strains (!)

UV doesn't work on these chemotypes

Then, 400ppfd for flowering lol. It's also established UVB works better with high irraduance, because the photorepair then works better 400ppfd is starving a plant.

ritoMox · Sep 1, 2022

testiclees said:
Ive been using this rig for a couple months.

"Dutch Passion, one of the worlds oldest seedbank companies, has tested the MIGRO UVB to determine the effect on terpene levels. They ran a controlled test in a side by side grow, one side with UVB, one without. There was a 19% increase in terpene levels under the UVB fixture, some terpenes increasing by almost 50%. Increased terpenes mean increased flavour and smell. Research also indicates increased terpene levels can lead to a more complex and satisfying effect when consumed". LINK

Yes, Sir

MIGRO UV VIDEO'S

ritoMox · Sep 1, 2022

N1ghtL1ght said:
Yeah, ignore that BS study, it's rigged, twice.
Genetics used:
‘Low Tide’ (LT) and ‘Breaking Wave’ (BW)
both high-CBD strains (!)
UV doesn't work on these chemotypes
Then, 400ppfd for flowering lol. It's also established UVB works better with high irraduance, because the photorepair then works better 400ppfd is starving a plant.

Went right over my head Thank you

N1ghtL1ght · Sep 1, 2022

N1ghtL1ght said:
Genetics used:
‘Low Tide’ (LT) and ‘Breaking Wave’ (BW)
both high-CBD strains (!)

I need to correct this to
"mixed"-chemovars, but still, both carry more CBD as THC and are labelled as 'medical' strains. That means that at some point in time the ancestors of these strains had been crossed with a 'high-CBD' chemovar. And these are known to not respond to UVB treatment - as Lydon back then did demostrate.

His original paper actually goes into great length to discuss the various theoretical explanations and these alone give insight into a broader understanding of all the interrelating factors that can trigger a higher cannabinoid content.

The CBD cannabis types originate from East-Europe, even north & middle Asia and these have been separated (by human domestication) already 3 thousand years ago from its original habitate in central Asia.

Most strains today cultivated or sold are actually type-I high-THC chemovars. But most of them are polyhybrids, and there is no proof that all those genetics still are able to respond positively, due to loss of responsible genes. Over decades of "non-UV" HPS or LED cultivation it won't matter. But the science occassionaly still hands out a study or two showing how moderate or pulsed dosis of UVB creates a number of positive effects. The plant can easily repair, compensate the damage (plants do have energy surplus) but what follows in response is a cascade of internal reactive pathways that beneficial. It's a way to induce systemically acquired resistance.

ritoMox · Sep 1, 2022

N1ghtL1ght said:
I need to correct this to
"mixed"-chemovars, but still, both carry more CBD as THC and are labelled as 'medical' strains. That means that at some point in time the ancestors of these strains had been crossed with a 'high-CBD' chemovar. And these are known to not respond to UVB treatment - as Lydon back then did demostrate.

His original paper actually goes into great length to discuss the various theoretical explanations and these alone give insight into a broader understanding of all the interrelating factors that can trigger a higher cannabinoid content.

The CBD cannabis types originate from East-Europe, even north & middle Asia and these have been separated (by human domestication) already 3 thousand years ago from its original habitate in central Asia.

Most strains today cultivated or sold are actually type-I high-THC chemovars. But most of them are polyhybrids, and there is no proof that all those genetics still are able to respond positively, due to loss of responsible genes. Over decades of "non-UV" HPS or LED cultivation it won't matter. But the science occassionaly still hands out a study or two showing how moderate or pulsed dosis of UVB creates a number of positive effects. The plant can easily repair, compensate the damage (plants do have energy surplus) but what follows in response is a cascade of internal reactive pathways that beneficial. It's a way to induce systemically acquired resistance.

Cannabis Confusion/The History of Afghan/Skunk

THIOLS ENTER THE EQUATION

In 1989, William Wood, a chemist at Humboldt State University (how ironic) discovered that thiols were the key component to the excretion and smell of the North American skunk animal.

Then in 2001, researchers at the University of North Carolina and the University of Gent in Belgium, published research into what makes beer smell skunky. The research showed that beer shares a similar thiol compound to the same one that is produced by skunks. Thiols are a chemical found in humulone, which is a compound found in hops.

From the article in Discover Magazine June 29th, 2012:

“Shellhammer explains that when ultraviolet light hits the humulone, a part of the molecule breaks off and binds with the sulfur in the beer, creating the thiol. “If you walk outside with a nice yellow beer like a pilsner on a summer day, the change is happening almost immediately,” he says.

He adds that in Europe and elsewhere, this is known as “light-struck” beer, not "skunky" beer, since skunks are not native to Europe.

Complicating matters is the fact that humans can smell thiols in parts per trillion, Shellhammer says. We perceive the other aromatic components of beer at parts per million. A tiny bit of thiol can overwhelm everything else.

Both hops and cannabis naturally produce thiols. They also both produce some of the same terpenes, fragrant chemical compounds, including humulene (which is not chemically related to humulone), caryophyllene and myrcene.

That’s because hops and cannabis are in the same plant family, Cannabaceae. If you analyze the oils extracted from each plant chemically, Shellhammer says, they are similar. “When we analyze the compounds in hops,” Shellhammer says, “Sometimes I walk by the lab and it smells like we are analyzing cannabis.”” LINK: Cannabis Confusion/The History of Afghan/Skunk

Is UV supp really needed w LEDs???

Is UV supp really needed w LEDs???

MIGrampaUSA

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