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

[brotherjericho]

Interesting, so the mercury vapor lamps don't generate much heat on their own? I would have thought they would. I might check it out, thanks!

Oh, btw, my tent is just 2x2 and I usually grow 3-4 plants in there at a time. I could put a t5 in there, and I even have an extra fluoro ballast lying around, just don't want the plant to be against the bulb. I can position the MV lamp if it does not generate that much heat.

Thanks!

 

[cannawizard]

^^ I can get that, but my flower tent really does not have the room for t5 bulbs, nor do I want the extra heat of mercury vapor. So that leaves me with the CFL lizard bulbs, which you say are practically worthless. So (in my case) UVB just isn't worth it.

CFL uvb 10.0 bulbs aren't "practically useless".. its how I started experimenting and seeing the results of uvb lighting supplementation (with HPS), it works. Does it have the same uvb levels as recorded under clear skies outdoors? = No. But does it alter the "high", = Yes. Why? Well that's the tricky part, enjoy researching what happens on a molecular level (trichrome synthesis / enzymatic reactions) , the science is still riddle with Qs left in the "gray zone"..

Kite is just telling you the parameters that growers have found which correlate to the same outdoor uvb levels, that's why lizard cfls actually work.. but at the same time its not enough uvb needed to get certain "reactions/results"..

Uvb is worth it, but you gotta know what your doing with it~

 

[Kite High]

Yes, plants do better NOT exposed to UV (I can't speak for cannabis). I found this out in my months of research of covering materials before constructing a large greenhouse. All greenhouse covering materials exclude up to 100% of UV with the exception of glass.



Quick Google got me this - http://www.gardenguides.com/132133-plants-ultraviolet-light.html

UB

http://link.springer.com/article/10.1023/A:1009706806427
http://books.google.com/books?hl=en&lr=&id=9OH9SVEVE7kC&oi=fnd&pg=PA157&dq=beneficial+uv+plant+exposure&ots=PfZ5ekv8y1&sig=k3gSHpWrFcUWVxQqusArbyt__hs#v=onepage&q=beneficial uv plant exposure&f=false
http://www.sciencedirect.com/science/article/pii/0166354289900703

 

[Kite High]

CFL uvb 10.0 bulbs aren't "practically useless".. its how I started experimenting and seeing the results of uvb lighting supplementation (with HPS), it works. Does it have the same uvb levels as recorded under clear skies outdoors? = No. But does it alter the "high", = Yes. Why? Well that's the tricky part, enjoy researching what happens on a molecular level (trichrome synthesis / enzymatic reactions) , the science is still riddle with Qs left in the "gray zone"..

Kite is just telling you the parameters that growers have found which correlate to the same outdoor uvb levels, that's why lizard cfls actually work.. but at the same time its not enough uvb needed to get certain "reactions/results"..

Uvb is worth it, but you gotta know what your doing with it~

I am finding in research that the uvb provides energy which is used to promote the synthase production that produces thc and thcv. The stage before the actual production of the cannabinoids is the production of synthase, ie protein enzymes responsible for the individual cannabinoids.

 

[brotherjericho]

http://www.reptileuv.com/megaray-eb-60-watt-flood-uvb-lamp-kit.php

60w kit, might be time to break out the Visa!

 

[Kite High]

As you can see those state backorder but I work with this guy a lot and these will not be coming back. I have the last 4 Zoo mv ext. ballasted 60 watt lamps. However if you write to the below link and inquire as to their ext. ballasted 60 mv they will give you the cost and availability. Remember these are spot lamps with a very narrow beam so moving it or the plants around will be required.

http://westronlighting.com/about-videos/contact/

 

[brotherjericho]

As you can see those state backorder but I work with this guy a lot and these will not be coming back. I have the last 4 Zoo mv ext. ballasted 60 watt lamps. However if you write to the below link and inquire as to their ext. ballasted 60 mv they will give you the cost and availability. Remember these are spot lamps with a very narrow beam so moving it or the plants around will be required.

http://westronlighting.com/about-videos/contact/

Yeah, I did see that. Oh well, got excited over nothing . What is your opinion on these? http://www.exo-terra.com/en/products/sunray_bulb.php

Not externally ballasted, but much lower wattages (less heat), and it appears they are also spot lights.

 

[Kite High]

The exo-terra cfl's I tested sucked. Write Westron. The price is reasonable and they are very good with customer service.

 

[Malevolence]

Kite High,

What do you think about this?

https://www.rollitup.org/advanced-marijuana-cultivation/109750-uv-light-max-thc.html#post9044406

I know its an old post but its an ongoing topic..

Anyone attempting to use UVB light for flowering that DOESN'T want to degrade THC levels to CBD and CBN should be careful with your flowering phase times.. My recent experience showed me that the plant matures (trichs start going amber early) about 1-1.5 weeks quicker if you use UVB lights 12/12 at flowering time. This doesn't mean you'll have nice tight nugs though..

We are going to have to balance the UVB exposure somehow to get more and tighter buds before the THC degrades.

This time around I'll be introducing UVB light at about 3-5% of my total light output in week 2 of flowering and shutting it off 1 week before flush.. Hopefully this will balance out the maturation rate with the bud grow rate and create loads of resin..

Its an experiment well worth trying.. I'll be posting it in a grow journal if I can get over an old habit of not creating evidence and take pictures of my grow..

 

[Kite High]

Bs. Never happened to me. He fucked them up with heat from the bulbs not UVB
thc does not degrade into CBD but just CBN. No amber trichs no CBN. I use UVB from sprout. Same lighting schedule as the main lights.

 

[cannawizard]

Lol.. THC+ degrades into CBD.. now thats funny~

 

[Pepe le skunk]

Quick question about UVB lights and Powdery Mildew? Anyone running UVB lights have any PM issues in flower? Please say if yes or no. Might be a good preventative for PM.
Thanks for the responses in advance.

 

[Uncle Ben]

Quick question about UVB lights and Powdery Mildew? Anyone running UVB lights have any PM issues in flower? Please say if yes or no. Might be a good preventative for PM.
Thanks for the responses in advance.

Have any photos of plants infected with PM? I'd like to see them please.

 

[Kite High]

Quick question about UVB lights and Powdery Mildew? Anyone running UVB lights have any PM issues in flower? Please say if yes or no. Might be a good preventative for PM.
Thanks for the responses in advance.

Never had pm

 

[Pepe le skunk]

Have any photos of plants infected with PM? I'd like to see them please.

UB please see PM on page 5 of this thread. https://www.rollitup.org/marijuana-plant-problems/614032-powdery-mildew-please-help-5.html

It is under magnification for PM. Don't want to disrespect Kite's thread on UVB with PM other than to find out if UVB cures it or stops it.

 

[Kite High]

UB please see PM on page 5 of this thread. https://www.rollitup.org/marijuana-plant-problems/614032-powdery-mildew-please-help-5.html

It is under magnification for PM. Don't want to disrespect Kite's thread on UVB with PM other than to find out if UVB cures it or stops it.

dilute skim milk 6-1 with water and a drop of dishsoap....mist the plants

ps- also this isnt my thread

 

[Pepe le skunk]

dilute skim milk 6-1 with water and a drop of dishsoap....mist the plants

ps- also this isnt my thread

Ok. Don't want to disrespect the original thread starter of this great thread.

PM has shown it's ugly head on these new clones I received of some Jedi/Darkstar cross. The person they came from didn't take care of them as they had Fungus nats in the soil and PM started on the leaf's after 3 days of rain and high humidity. Humidity was in the 60% to 72% for 3 days before I could properly ventilate the area. Clones are 2 ft tall now. but that damn PM has shown it's ugly head. I'll give the skim milk a try.

Thanks again for your great insite and help. Any comments are greatly appricated.

 

[cannawizard]

I would assume UVc would be more suited to help with PM problems since its used in hospitals as (short wave) germicidal agent.. Not sure if UVb would be useful in combating a PM problem..

 

[Moebius]

UVB helps the plant protect itself from phytophagous Insects. Supplemental UVB has been shown to increase this effect.

a scientific paper for any interested; http://aob.oxfordjournals.org/content/99/1/103.full.pdf

 

[Kite High]

I would assume UVc would be more suited to help with PM problems since its used in hospitals as (short wave) germicidal agent.. Not sure if UVb would be useful in combating a PM problem..

UVC would also potentially harm the plant as it alters/destroys chromosomes