UVB BULBS

[Opie Yutts]

Yeah, I got a sativa dom. that takes almost 13 weeks. I blame the genetics and superthrive, which I just learned will extend flowering.

I say again: SuperThrive should not really be used for flowering.

[mariboogie420]

hey i'm new to this site, but i have only 2 10% uvb repti-sun cfl's and 4 sun light cfl's all on for 20 hours a day. the three plants seem healthy, but the plants leaves that are near to the repti-sun cfl's (about 4 inches away) have turned shiny orange-brown and silky and the plant is still alive and other than that the leaves look healthy. any advice, i am not trying to throw away the repti-sun because they were 45 each at the store, even though my friend had a five finger discount. any advice?

[mariboogie420]

hey i'm new to this site, but i have only 2 10% uvb repti-sun cfl's and 4 sun light cfl's all on for 20 hours a day. the three plants seem healthy, but the plants leaves that are near to the repti-sun cfl's (about 4 inches away) have turned shiny orange-brown and silky and the plant is still alive and other than that the leaves look healthy. any advice, i am not trying to throw away the repti-sun because they were 45 each at the store, even though my friend had a five finger discount. any advice?

[keeko]

a picture would help a lot.....

and next time leave the part about being a five finger discount out of the topic. you wont get much respect here when people find out you hang out with theifs.

[GreenDestiny]

Yup, you guys need to read this: http://www.greenmanspage.com/guides/thc.html

Interesting stuff there...

According to that article:

Cannabinoid pathway: Anywhere in this pathway UVB does a better job than UVA in energizing a phytochemical reaction that will produce more fully realized THC because "all cannabinolic compounds show an absorption maximum between 270 and 280 nm in the ultraviolet region."

So then if those findings are correct, that would mean the most beneficial range of 270-280 doesn't quite fall into the UVB category... it's UVC.

Every source I find will list the cutoff between UVB and UVC at 280 or 290 nm. That's just splitting nanohairs! Never-the-freakin-less, anything between 270 and 280 is still gonna be considered as UVC.

Actually, who cares what it's called, right?? It's close enough.
As long as it works!
The UVB light should work great but if you want to get technical about it and purchase some LEDs, then perhaps that 270-280nm might be your best bet... but good luck figuring out how many individual LEDs you need for that!

Oh yeah, and if you want more confusing stuff to read about it, check this out:
Comparison of three advanced chromatographic techniques for cannabis identification
3rd paragraph of the Findings section mentions all that UV absorption stuff with and a couple graphs to look at.

And now for another bit of random info from iguanaden.org
"Most tube-style UVB bulbs lose their effectiveness in about 6 months, even though they still produce light.

I'm not even growing at the moment yet I'm starting to get obsessive over this stuff.... someone please put me out of my sobriety

[Opie Yutts]

GD, thanks. Interesting.

mari, I agree with keeko on both counts. I hate thieves, and we need a picture of the problem. Pimping and stealing are not things to be proud of, and I don't understand how that can get turned around for anyone. I've never heard of leaves turning shiny and silky. Even a picture from a phone camera would be better than nothing. You need 50 posts to put up an image here, but you could always supply a link to your image on a free image hosting site, like photobucket.

[keeko]

GD, thanks. Interesting.

mari, I agree with keeko on both counts. I hate thieves, and we need a picture of the problem. Pimping and stealing are not things to be proud of, and I don't understand how that can get turned around for anyone. I've never heard of leaves turning shiny and silky. Even a picture from a phone camera would be better than nothing. You need 50 posts to put up an image here, but you could always supply a link to your image on a free image hosting site, like photobucket.

:thumbsup: thanks bud, "must spread before giving to OY again"

[dindyman]

I was told that these bulbs would be the absolute best by someone who has done thois before with great results...they are mercury vapor bulbs that produce the right amount of uvb used to properly mimic the sun in a tropical climate, 250-300 microwatts per square centimeter (uW/cm2) of UVB and 2,000uW/cm2 of UVA at a 3 foot distance...most tropical places get about 400 uW/cm2 of uvb at mid day so id say about 2 feet away, use this bulb about 4 hours in mid light cycle for best results, check out the links to read more and tell me what you think, i was looking at the external ballasted zoo one, these also last a hell of alot longer than a normal reptile uvb light that might only last a maximum of 5-`6 months before it looses its power and stops producing uvb light

ReptileUV Mega-Ray Mercury Vapour Lamps for Reptiles - Test Report UV Guide 2006

Mega-Ray® & ReptileUV Products

[stinkyattic]

You get banned here for bragging about theft btw...

On the subject- I just feel the need to interject here that while strains grown at high altitudes and subjected to more intense UV light do produce more resin (along with less yield due to the thinner air), for 99.9% of growers, the extra cost of purchasing and operating supplemental UVB bulbs simply doesn't make sense for one of a number of reasons, the most common one being that other factors in the grow are not yet optimized. This is similar to running CO2- but even less likely to make the grower say, 'ohhey, that was like, TOTALLY, worth it!!!'

So as with all other things, get the basics locked down tight before spending money on what is simply a gimmick in the hands of a less experienced grower.

[cture]

Thank you all for your thread guys! I have found this lamp and starting to use it!
1 lamp per 1 meter ^2 This will provide a highland uv b or equatorial UV b
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