UVA/UVB the real deal. A must read topic for all growers.

VTMi'kmaq

VTMi'kmaq

Well-Known Member
Rrog said:
:) Are you asking if I have? Yep Mega Ray. I use a simple metal lamp used for chicken coops. Clamp that bastard where it needs to go.
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Now that's what im talking about redneck engineering, ala macguyvering shit outa fun and necessity!:mrgreen:
 
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anzohaze

Well-Known Member
I am sure you no bit the reptile uv dight has numbers saying whats what at certain distsnce but thats all I jo and they say from there test the sun outs off blah blah and this light blah blah butni wanna order one and try it. How long has or does a bulb last.
 
Rrog

Rrog

Well-Known Member
LAsts a while. What I liked about that lamp was the testing over time after burn-in. Had good output over time.

I just give 15 minute blasts, but I've been using it for 4 years in very small grows. If it broke I would buy another one, so I'm satisfied.
 
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HrilL

Active Member
I've been using 3 of these http://www.lightyourreptiles.com/ard3t546in54.html for about a month now. Vegged with them on 24/0 for 3 weeks as well. I did notice a slight increase in growth but that could also be attributed to the 3 6400k T5's I also added. I have 3 dual 4' T5 lamps over my 4.5x4.5' space with 2 450watt LED(240watt actual draw) slightly offset. I will show some pictures when I get home and the lights come on. Had them at about 24 inches initially since I needed my two LEDs at that hight at the time and if I had them lower I would have got light blockage from them. So I've been keeping everything even. Right now one plant is about 6 inches from them and the others are about 16-10. These lights also give off a decent amount of visible light. They're almost on par of brightness to a 6400k T5. I've now added two of these in my Veg space as well that I just leave on 24/0 with my other light. Hard to say if I've noticed much difference in growth but adding them to my plants that were already about 2 ft and mature made them all show preflowers. One strain I never worked with that is not supposed to be an auto just started flowering full on in there with 24/0 light as well. Just going to let it go in my veg space since I don't have room in the other.
 
Pepe le skunk

Pepe le skunk

Well-Known Member
Rrog said:
I'd be interested in any links to "today's science" also. That's not sarcasm. I'd really be interested.

This thread had a very comprehensive back and forth and many studies were referenced. http://forum.grasscity.com/indoor-medical-marijuana-growing/336317-uvb-lights.html/page-10
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Cool would like to read that thread. Here are a few others.
Hope this helps.

Here is the basic science. It is a you tube video of the process at the cellular level. http://www.youtube.com/watch?v=lfiI78uN3Ks

Here is a good video on UVB light intensity and understanding the inverse square rule of light as you move away from the source.
http://www.youtube.com/watch?v=AUu24MNO2Ho


And a thread on UVB in general. https://www.icmag.com/ic/showthread.php?t=260046



HrilL said:
These lights also give off a decent amount of visible light. They're almost on par of brightness to a 6400k T5. I've now added two of these in my Veg space as well that I just leave on 24/0 with my other light. Hard to say if I've noticed much difference in growth but adding them to my plants that were already about 2 ft and mature made them all show preflowers.
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UV light in invisable below 380nm or so. Most of those reptile bulbs contain phousphers that also produce visable light in that 6000K to 7500K range. They are better than regular bulbs because they have the UVB.


I will say that after clones come out of the domes I do place them in a humidity tent for a few days under 2 48inch 10% uvb bulbs. In a week or so I remove the tent flap and expose them to room conditions under the same uvb bulbs. Also seen sex after a few weeks to months depending on strain. Not sure it trigger's anything so early in veg but they are bulbs that I had and could use for clones transfered to dirt fresh out of the cloner. Trichomes not building in massive numbers at that point so UVB light exposure might not have a drastic effect..
 
Rrog

Rrog

Well-Known Member
Coo vids and data, but that Grow Room video with "marijuana man" has some major BS in it... just so the world knows. He takes great liberty with some of the mechanism, including the label that resin is a defense of UV-b which it isn't at all in my mind.
 
Nizza

Nizza

Well-Known Member
from mel thomas's book ::edit:: cannabis cultivation

"three 10-minute exposures of UV light during the peak hours of the light cycle will result in up to a 10% increase in yield"

can someone validate this or explain why or why not you would do more/less exposure or how "acclimating" to a constant exposure would be beneficial . i have a couple 2ft t5 fixtures i was thinking of getting the reptile bulbs for.
was planning on running them 10 minutes every 45 minutes during 2h 15min peak day (5h 7m 30sec into the day cycle, then 5h 52min 30sec, and 6 h 37m 30s)
 
Rrog

Rrog

Well-Known Member
Never heard anyone claim increased yield before. I have only ever heard the exact opposite with too much / too intense UV-b.

I would tend to agree with the short exposures being enough to get the desired result. That's what I do.
 
Nizza

Nizza

Well-Known Member
cool, cause i like the idea of not having to run the uv lighting all the time, so i can look in there. I do have to get some HPS sunglasses, anyone know what type of sun glasses these are? I wanted to find out so i could maybe find a cheaper pair than found at a grow store

know that if using UV lighting, it is really bad for your eyes and skin!
 
Sunbiz1

Sunbiz1

Well-Known Member
Rrog said:
Never heard anyone claim increased yield before. I have only ever heard the exact opposite with too much / too intense UV-b.

I would tend to agree with the short exposures being enough to get the desired result. That's what I do.
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Some true humor for U today. I had the bulbs on wearing sunglasses in the flower room last week while working. I also have a military type haircut, as in very little hair.

The top of my head got sunburned in less than 10 minutes.:mrgreen:

And the plants love it, leaves go straight into prayer mode when I turn lamps on. Like you, I use them sparingly...no more than 30 minutes/session.

:peace:
 
Pepe le skunk

Pepe le skunk

Well-Known Member
Rrog said:
but that Grow Room video with "marijuana man" has some major BS in it... . He takes great liberty with some of the mechanism, including the label that resin is a defense of UV-b which it isn't at all in my mind.
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Not sure what BS you speak about? Can you be more specific? It has been long understood that the resin, more specific the trichcome works as a sunscreen to sheild the plant from higher quantities of UVB. One reason plants grown at higher altitude usually are more potent then the same plant grown at sealevel because of the thinner atmosphere and higher quantities of UVB exposure. Think highland vs lowland in columbia or thailand. Or Afghanistan. Reports that even a few thousand feet can be more potent the higher you go. If you take the same clone of a plant this experiment can be and has been shown to be true.
Nizza said:
from mel thomas's book ::edit:: cannabis cultivation

"three 10-minute exposures of UV light during the peak hours of the light cycle will result in up to a 10% increase in yield"
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Look at the date that book was published because the sun does not give bursts of uvb but an all day exposure. Also the technology of the light phosphors has only really advanced in the past 10-15 years for higher output over a large area. Have been doing UVB and seen the results on many crops. I leave mine on the entire flower light cycle with no adverse effects. Look at the lux strength and distance video for reference and exposure comparing shaded area to higher levels of uvb the closer you get. Hope that helps. It is understood genetics or different strains and breeding has the most effect however the extra UVB allows the plant to produce the maximum amount of sunscreen or resin thc in the plant. It allows it to live up to its potential.
Hope that helps.
 
Pepe le skunk

Pepe le skunk

Well-Known Member
MH and HPS has very little if any UVB and that can be confirmed with a UVB handheld monitor. So the phosphors are only contained in florecent type tubes and now some LED lights. Also the glass in the light fixture also cuts the UVB of hese bulbs and is the reason bare bulb grows contain some UVB, specifically MH bulbs.
I turn off the uvb bulbs if I am in room for more than 10 minutes and try not to look right at the light. I also rotate the exposed side every few days for better exposure to the uvb light when flowering.
 
homebrew420

homebrew420

Well-Known Member
I have read the myths and not once have I ever seen real difference in gland production. If uvb chemically change thc to thc-a so whay. Thats what happens when combusted. No? If there was a great deal of truth I think more would be looking into it.
How much of and increase? Noticable?
Has anyone ever done a blind trial? Doubt any difference would be noticed.
Tried the cmh lamps for a bit, always beleiving I could get a little something extra. What I noticed changed, with quality and potency, were my skills as a grower. Understanding what is needed for stress free growing.

Would love to be part of the judges if this experiment ever goes down. Haha

Peace
 
Pepe le skunk

Pepe le skunk

Well-Known Member
homebrew420 said:
. Thats what happens when combusted. No? If there was a great deal of truth I think more would be looking into it.
How much of and increase? Noticable?
Has anyone ever done a blind trial? Doubt any difference would be noticed.

Would love to be part of the judges if this experiment ever goes down. Haha

Peace
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Check out the link. This guy did UVB and no UVB and had it tested. UVB exposed plants tested higher. Also the pictures showed the difference. Look on IC they have results.
Hope that helps.
 
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