UV lighting thread

This thread is the longest conversation I've found on the topic so yeah...could use more info.

I did find this paper from the University of Maryland, written in 1986: https://smartgrowtechnologies.com/wp-content/uploads/2015/09/UVB-RADIATION.pdf.

And here's a video from Dutchman's Medical Marijuana: [video=youtube;QRAU0ziyDpo]
[/video]

I just got a couple of lights (to add to my LEDs) but this is my first grow and I don't want to screw it up, so I'll probably try them in the last couple weeks of the flowering stage/bloom cycle, one hour a day. If they don't appear to do any damage, I may increase them by an hour each day.

I read some other threads that seemed to indicate that giving them too much too soon can damage the plants or cause the trichomes to reach their peak and force an early harvest.

Some solid beta would be great so anybody who's tried this - would love to hear about your results.
 
Advocate420 said:
Finally some interaction!

They are 75% UVB and 25% UVA T5 bulbs ( clearly more powerful then any aquarium or reptile bulbs. I learned after scorching my eyes.) Oops.
Sounds like I may be on the right track. I had s feeling it was like high stress training. Damaging so it repairs stronger but doesn't die. I'm going to have to be careful with these bad boys.

Makes a lot of sense.
Click to expand...
Be careful it can cause skin cancer
 
Thank Avid you are so right.
So far for UV lighting I've learned my exposure lessons. Shit is no joke. Way more powerful than normal UV exposure. The eye and skin damage with these potencies of UV lighting is no pillow sticker general warning, UV light is dangerous as hell. In the videoposted he puts his hand under light and say it won't burn you. Very wrong. Learn from my mistake. Even minutes of exposure and you will be hating life. Again I'm not talking aquarium or reptile bulbs. I'm talking horticulture UV lighting.
 
Okay. Experiment 1 UV Lighting and pest control.

Well if a few minutes of exposure to uvb lights I scorched my eyes. The fox farms ocean forest soil I've bought on separate occasions are responsible for a microscopic white little soil mite. I think it to be a predatory mite with several immunities. UVC lighting has known germicidal properties and no use in growing plants. Other UV wavelength UVA and UVB less information is available.

The experiment. To kill possible beneficial mites

Pot 1 Dutch Delight seedling, 1 hour exposure to UVB /UVA lighting.

Question: Any decrease or absence of soil mite life...
 
Advocate420 said:
Okay. Experiment 1 UV Lighting and pest control.

Well if a few minutes of exposure to uvb lights I scorched my eyes. The fox farms ocean forest soil I've bought on separate occasions are responsible for a microscopic white little soil mite. I think it to be a predatory mite with several immunities.
Click to expand...

in you opinion, harmful, beneficial, or neutral,,, on the mites?

UVC lighting has known germicidal properties and no use in growing plants. Other UV wavelength UVA and UVB less information is available.

The experiment. To kill possible beneficial mites

Pot 1 Dutch Delight seedling, 1 hour exposure to UVB /UVA lighting.

Question: Any decrease or absence of soil mite life...
Click to expand...

will be interesting to see results, for sure. I wonder what UV is on the cheap chinese LED boxes on Amazon? It just says UV, not UVA or UVB..
 
BoomShakalaka said:
in you opinion, harmful, beneficial, or neutral,,, on the mites?



will be interesting to see results, for sure. I wonder what UV is on the cheap chinese LED boxes on Amazon? It just says UV, not UVA or UVB..
Click to expand...

After hours and hours over days of reading I'm settled on it as a beneficiary species I think is likely common in fox farms soil. Peeps might not be seeing these things they be tiny. I have pics on the path to least resistance signature.

I know LED lighting is recognizing UV wavelengths. Both UVA and UVB from what I read. How powerful and how long they are effective is one concern I would have. UV lighting I think is similarly to any fluorescent style lighting it doesn't venture far from the source. So is a little bulb added to led lighting really adding UV lighting. I'm skeptical.


Okay UVA/UVB pest resistance mite kill experiment initiated. Here is plant and health prior exposure. Going to try 1 hours.
Got my sunglasses on headed to the radiation station ! Updates to follow.
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Advocate420 said:
Okay. Experiment 1 UV Lighting and pest control.

Well if a few minutes of exposure to uvb lights I scorched my eyes. The fox farms ocean forest soil I've bought on separate occasions are responsible for a microscopic white little soil mite. I think it to be a predatory mite with several immunities. UVC lighting has known germicidal properties and no use in growing plants. Other UV wavelength UVA and UVB less information is available.

The experiment. To kill possible beneficial mites

Pot 1 Dutch Delight seedling, 1 hour exposure to UVB /UVA lighting.

Question: Any decrease or absence of soil mite life...
Click to expand...

I'm actually researching this for my job right now, and although I'm not going to share every single detail because I'm under strict NDA's and privacy agreements... UV-B and UV-C do show promise in killing spider mites..as well as some blue light also will kill them. however, there are drawbacks to each..there is plenty of research out there though and easy to find. Just google "spider mites UV-B abstract" and you will find a couple dozen studies...I wish I could share more, but just can't due to my agreements.

In the studies UV-A wasn't showing much promise, blue light and UV-B were the best for mite disruption although it wasn't a 100% mortality in any tests, it did significantly reduce their counts.

UV-C is very very very dangerous, and I don't recommend anyone using it for anything! UV-B does show promise in both mite control and plant benefits but I still have more research to do.
 
Icemud said:
I'm actually researching this for my job right now, and although I'm not going to share every single detail because I'm under strict NDA's and privacy agreements... UV-B and UV-C do show promise in killing spider mites..as well as some blue light also will kill them. however, there are drawbacks to each..there is plenty of research out there though and easy to find. Just google "spider mites UV-B abstract" and you will find a couple dozen studies...I wish I could share more, but just can't due to my agreements.

UV-C is very very very dangerous, and I don't recommend anyone using it for anything! UV-B does show promise in both mite control and plant benefits but I still have more research to do.
Click to expand...

I have no such gag orders. I suspect that is some of what Is getting touched on here with a UV thread. We are all creatures of science and well common sense may apply. Thank you for your guidance.
Thank you or the key word search I was tying it in as you were posting lol.
 
UVA/UVB mite kill experiment

54w T5 75%uvb/25%uva horticulture bulb, 6 inches above soil.

@ 5 min no noticing difference to plant or soil mite.

@30min to the eye there is a noticeable population decrease but still plenty noted, no noticeable difference to plant.

@60min Have not disturbed soil any yet. Possibly gave the mites a tan, still present. If there is a difference in the plant It appears more pale, not as dark green.

Going to shut her down for today. Hoping to get more gems from ya'll
I'll follow up tomorrow to see if I notice a delayed effect. Hopefully we rearranged their DNA a little.
 
Hey Advocate, check your PM.. :)
 
Advocate420 said:
My first pm communication, yay
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Its a huge study on UV light and medicinal plants :) I can't post links in the forums and it was way too long to copy and paste, but give some really good info on UV and how it effects cannabis. enjoy!
 
Okay so the one hour exposure was kinda hard on the baby plant and the mites didn't mind at all. I did an additional hour under the UV before lights out. The plant has some weird new growth and obvious burns to the leaves the day after. Mites I think we're in lawn chairs laughing at me.
 
Icemud said:
Most of the light they receive is UVA which is less harmful than UVB and UVC. Most UVB and UVC get absorbed by water and gasses in the atmosphere so very little UVB hits the surface, and little to no UVC hits the surface of the earth.
Click to expand...
More to think about:)

Ultraviolet (UV) light falls in the range of the EM spectrum between visible light and X-rays. It has frequencies of about 8 × 1014-to 3 × 1016-cycles per second, or hertz (Hz), and wavelengths of about 380 nanometers (1.5 × 10−5-inches) to about 10 nm (4 × 10−7-inches). According to the U.S. Navy's "Ultraviolet Radiation Guide," UV is generally divided into three sub-bands: UVA, or near UV (315—400 nm); UVB, or middle UV (280—315 nm); and UVC, or far UV (180—280 nm). The guide goes on to state, "Radiations with wavelengths from 10 nm to 180 nm are sometimes referred to as vacuum or extreme UV." These wavelengths are blocked by air, and they only propagate in a vacuum.Most of the natural UV light people encounter comes from the sun. However, only about 10 percent of sunlight is UV, and only about one-third of this penetrates the atmosphere to reach the ground, according to the-National Toxicology Program-(NTP). Of the solar UV energy that reaches the equator, 95 percent is UVA and 5 percent is UVB. No measurable UVC from solar radiation reaches the Earth's surface, because ozone, molecular oxygen and water vapor in the upper atmosphere completely absorb the shortest UV wavelengths. Still, "broad-spectrum ultraviolet radiation [UVA and UVB] is the strongest and most damaging to living things," according to the NTP's "13th-Report on Carcinogens."
 
I ended up getting a couple of 48" UV lamps from Petco, which they call "ZooMed ReptiSun T5 HO Terrarium Hood," and replaced the bulbs with two 46", 54 watts 10.0 UVB bulbs, also from Petco. You can order them separately online for about $80 for the hood plus replacement bulb or just go with the bulb that comes with it. So $160 for the setup of two lamps with bulbs for a 77" square tent.

Since there's no built-in way to hang them, I strapped them in 18" zip-ties--two on each end--and attached those to ProGrip Hangers (pulleys) with 2" carabiners. If you don't tighten the ties down all the way, you can swivel the lamps to tilt up or face flat down to ensure coverage to all the buds. The pulleys allow you to raise and lower them to increase (reach more buds) or decrease (for greater intensity) the UV light footprint.

So far, I've been giving them three hours of UV light a day (at the end of the 12-hour light cycle) and rotating between facing them straight down and tilting them inward to hit the plants that are directly under the LED lamps. I have not seen any damage to the plants or accelerated bud maturation (which is good, because I want the buds to get bigger before harvest) and the trichomes are still clear going into the 8th week of flowering.

As for increasing the THC? Since I don't have a control group, I won't really know. I'll just have to see how it all turns out.
 
For God's sake first and foremost protect your eyes! FULL EYE COVERAGE--GOGGLES--SO NO UV LIGHT GETS IN FROM THE SIDE EITHER. No, sunglasses are NOT enough!

This is incredibly important. You really don't want skin cancer on your face and cataracts any earlier than you need to. Even short wavelength blue light can damage your eyes. If you're gonna use UV, get serious and get professional. This is serious, dangerous stuff.

I used to work in a bioengineering facility where we used UV for DNA work. Lots of people would work for half an hour at a time wearing just googles instead of a full face shield and gloves as they were supposed to. Eventually they'd get Donald Trump tanning bed white circles around their eyes where the googles had been and suntan/sunburn on their hands.

I'm old enough now (60s) so that I'm seeing the long-term effects of just too much sunlight in my friends and myself. I have already have a slightly cloudy lens in my left eye and have had to have actinic keratoses burned off my face. A friend had to have full on facial surgery for skin cancer. Another friend has even had surgery on his arms and elsewhere from his hippy nudist days in Florida. (And of course UV can cause malignant melanoma, which is one of the worst cancers there is.)

The bottom line is, protect yourself from UV, ESPECIALLY from the industrial-grade UV lamp variety.

Better yet, just stick to visible light illumination and find some other aspect of your grow to optimize/hot-rod.

Take care of your skin (and especially your eyes). Your 60- and 70-year-old self will thank you. :)
 

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