Advice for UVB

[big twinn]

thinking about adding UVB to my 250watt HPS flowering cab. i have the space for 1-2 fixtures at the top. I plan to flash it on for 30 min. every 4 hours of 12/12. so it will be on for three 30min sessions a day. is this too much? too little? a waste of time?

how noticeable is the trichrome production? noticeably more potent?

is a 50 UVB too high or too little such as this:
http://www.petco.com/product/14564/Zilla-Slimline-Desert-50-UVB-T8-Fluorescent-Fixture.aspx

Thanks for your help

 

[Phaeton]

This thread jumped out at me, not 'cause I have any answers, but I have been remodling my veg room. UVB is on my list.

I have hung 8 T5's @ 54w each, six 6500K and two 460nm aquarium lights for coral growth. Another 8 are enroute, six more 6500K and two 420nm. Right now there are 22 T8's also, but these are coming down as the T5's show up, will be 16 on the walls only when done.

On the list are 4 T5's @ 28w desert 50 UVB lights and fixtures. My perusing through the internet shops ended up with the same lights all the reptile owners are warned against. The output is way more than rated with most of that in the shorter end.
My two sets of lamps are going to follow a tray of plants from clone to bud, I am using a larger amount of UV as I am supplementing 1400 watts of veg and 2800 watts of bud. Need a few watts of UVB to make it a real test. And full time with the regular lights, no flash.

Mine will start with my June tray, unless this has been documented already and is a dead end. Have not seen any indication of test results showing that yet.

Any information from grows supplemented by UV appreciated.

On that note I did use a pair of 40w T12 blacklights from clone to bud with no effect whatever. The output with the T12's is longer wave UVA only. Gonna try again with B and lots more of it.

 

[Oldmac]

I use UVb in my personal grow durring the flower cycle. It will help to ripen trichomes and get clear to cloudy to amber faster. Used during flower only it will not add any trichome production but will increase resin production.

Used from the begining of veg thru out the grow I found some strains increased trichome production, in my experiments 3 of the 5 strains tested showed a noticeable increase. One of the strains that did not was White Rhino, it packed trics on top of trics without UVb so if it added anything it just wasn't noticable.

In my grow I use Zilla 50 desert T5 2' tubes (4 of them) that are 18w normal output. Nobody seems to make T5 HO bulbs. I overdrive them to VHO levels of 40w each and only use them for 3 hrs during the middle of the photoperiod (high noon).

Keep in mind UVb is very DANGEROUS to your eyes, I would avoid going into your grow area while they are on, and if you must then wear UVb sunglasses....preferably those large, side protected ones old people wear after cataract surgery.

OM

 

[sm0k4]

You probably want a couple 26W T5 reptile lights. One on each side o the HPS for better coverage. Repti-Glo 10.0 is a good brand people like.

There have been studies on UVB and THC production and there seems to be a direct correlation to higher THC content with the use of UVB.

 

[big twinn]

Oldmac- you say used in flower in will only ripen the trichs faster. So should i even bother, as i want the buds to swell while the trichs ripen rather then ripening too fast? Also, can you explain what you mean as far as differences b/w trich production and resin production.

 

[Weezard]

Your on the right track.

Your on the right track.

"i want the buds to swell while the trichs ripen rather then ripening too fast"

And, you want to keep piling on the trichs without losing any to UV damage.
Too much UV will cause the resin globules to darken, then shrivel, then fall off!
The plant does produce more to replace them in a continuous process, but I figure, a globule fried, is a globule less.

I filter out the short UV in my greenhouse until the buds finish swelling.
Then it's "tan time" for up to a week to degrade some of the THC's "uppity" rush into a more soporific, analgesic, effect.

Jus' 2 pennies,
Oldmac is really your best "goto" guy for dis.

Aloha,
Weeze

 

[Oldmac]

First let me explain I did back to back experiments with my personal grow because 1) it is very well dialed in 2) my main light which is a LED/T5 hybred is located inside a 6" borosilicate glass tube that would block any UVb from the floros 3) my supplemental UVb lights are completely seperate.

When I talk about speeding the ripening I'm refering to the difference between for example White Rhino taking 63 days or so just to reach cloudy (peak THC level) and another few days or more to achieve a few amber (CBN/CBD degradation product of THC and is a depressant). With UVb by day 52 all are cloudy and I can reach a 25% amber in just a couple more days. Used as medicine it promotes sleep and pain relief or recreactionally "coach lock". It is worth noting that high trichome production is not necessarily a indication of a potent plant.

Weight will increase with the use of UVb due to an increase in leaf thickness including the small leaves associated with floral bracts. So the green mass is more at 52 days with UVb then at day 63 w/o. In my case with small SOG plants it ranges from .10 to .25 grams/plant (finished wgt), but at 144 single cola "plantlets" a increase of .25gr is an additional 1.5 oz per run.

BTW I never saw any increase in trichome production using UVb just during flowering. Some one suggested to me that it might/would do that if used from beginning of veg thru to finish. This past summer I over saw a three chamber test, UVb from start, UVb just flower and control of no UVb. Ran 5 strains and three showed increase in stalked capitate trichomes, two did not.

Which leads to the question of "increased resin production". Resin consists primarily of secondary metabolites or compounds that play no role in the primary physiology of a plant. While we usually gauge by the trichomes appearence you need to understand that there are 3 types of trichomes and that some of thier production is secreted out from the trichomes, much like pines excrete certian pine resins (not to be confused with sap).

There are three types of trichomes;
1) bulbous- these are the smallest, 15-30 microns, 1-4 cell foot/stalk 1-4 cell head that secrete resin under the cuticle and foot.
2) sessile capitate- these are medium size, 25-100 microns, 1 cell high stalk, 8-16 cell head and secrete onto themselves.
3) stalked capitate- the largest, contain a non-cellular cavity (sometimes called a globular capitate) raised stalk hgt of 150-500 microns. Mostly contain thier resin tho some is secreted on it self.

BTW, for Weezard wave: ) and others, I have found that not much more swell occurs between day 53 or 58 and day 63. When grown properly at optium conditions.

OM class dismissed.

Hey 'zard I hope you saw where I mentioned somewhere else, that between the ambient CO2 levels and high UVb levels in HI, you got no excuses not to grow good stuff outdoors.

 

[Phaeton]

This is vaguely pertinent as the result is I took the protective cover off a 300 watt halogen worklight allowing the marginal amount of UV present to come through.

The real reason is the new budding LED's being sold with enhanced long wave red, 740+ nm. Some sciency stuff about cell division.
But I'm looking at these claims and graphs and I pull up a site with the emission curve for halogen glowing at 4000K. Darn, 100% CRI with the major peak in red and lots under the curve in the 700nm to 800nm region that is now claimed as the main driver for enhanced bud production.
Ten dollars for a 300 watt halogen worklight, and it puts out all the frequencies of the LED enhanced budding light for that price. It costs 2 degrees per light in the budroom, dialed right back out no problem.
Unless a compelling reason exists I am giving my plants two of these every morning for 2 hours and putting them to bed with another 2 hours worth.
Set it up yesterday morning, this morning when I went in for morning chores I could feel the lights on the top of my head. The thermometer in the canopy held even temps and the fans went down to normal when the lights cycled off.
The red lights I use for budding peak at 630nm so if the claims are true this should increase both bud size and trichome number. My budroom is pretty dialed in so any real change will be noticeable.


Long explanation but what I'm curious about is the 300 watt halogen. The warnings include UV, Just how much actual UV is being emitted? I have not easily found an answer yet. Hoping somebody has looked it up and can just tell me faster than I can find it myself. I'm looking, but other priorities keep interrupting.:kitty:

 

[growshopfrank]

A nice compact UV lamp can be constructed using low wattage MH HQI (double ended) lamps and a pulse start ballast (70w or 150w) just avoid lamps labeled low UV

 

[Oldmac]

@growshopfrank; You are correct MH HQI bulbs do put out UVb, not sure how much vs. there light output, but that is like most bulbs....hard to quantify.

It should be noted that CMH bulbs put out UVa & UVb and that they are a good choice for small grows, since they only come in 250w and 400w. They have a great spectrum, better overall then either HPS or MH.

@Pheaton; The use of far red light controls photochrome, and that is the relationship between Pr (red 660nm) and Pfr (far red 730nm). This relationship controls plant stretch and it's use at the end of the photoperiod helps keep plants shorter with tighter internode spacing. This is the last light your plants should see before lights out. A large dose after main lights are off also fools the plants chemistry in to thinking the dark period is longer, up to 2 hrs more. Used first at the beginning of lights on it supposedly jumps starts the plant's photosynthesis but I have yet found scientific evidence for that, just the word of some greenhouse operators. I have found a science paper dealing with it's use at lights out and confirms the short plant theroy.

As I just mentioned it is hard to quantify UVb amounts without a proper meter. Reptile "desert 50" bulbs guarantee "50mw output at a certian distance (usually 12 or 18") depending on bulb.

BTW, I use incandescent halogen bulbs (GE Revels) as a far red source supplemental lighting in my personal grow and in a partnered aero/fog tray setup. Your use of that halogen work light might be a good choice to get the far red and some UVb together.

OM

 

[supermanlives]

great read . i tried reptile bilbs once with one strain and didnt see any difference. curious to others experiments.

 

[prune]

I use UVb in my personal grow durring the flower cycle. It will help to ripen trichomes and get clear to cloudy to amber faster. Used during flower only it will not add any trichome production but will increase resin production.


Keep in mind UVb is very DANGEROUS to your eyes, I would avoid going into your grow area while they are on, and if you must then wear UVb sunglasses....preferably those large, side protected ones old people wear after cataract surgery.

OM

UVB is a powerful oxidizer, and does not ripen trichomes, it ages them. Clear-cloudy-ruddy is just a visual tracking of the oxidation levels of the capitate reservoir. If you're not happy with how fast your plant is "rusting", you can accelerate the chemical break-down by adding UV light, ozone, high temps, really anything irritating will work...

I myself prefer the adage of "sugar beating vinegar" in the treatment of my wards, and leave the color changes of age to the curing process.

As to whether these spectrums can induce increased capitate gland production, my own side-by-side comparisons yielded inconsequential results. Certainly not enough to make it worth the probable side-effects for the committed grower.

 

[Oldmac]

Hello prune and welcome to the boards,

You are correct that UVb is a powerfull oxidizer... it is used for disenfecting, along with UVc that is even more powerfull.

THC and it's precursors are very UVb receptive. The membrane located between the stalk and the globular section is where that magic happens. The very shape of the globular capitate is designed by nature to take light from any angle and focus it on that membrane, producing THC (cloudy condition) and more will start to create CBD/CBN (amber condition) which is a degradation product of THC. Over exposure for long enough periods will completely destroy the globular capitate (as Weezard points out) and that's not good. But it will increase the production of THC and will also accelerate it's break down.

I base my opinion on not just on my own experiments but also on scientific white papers. Here's one that explains UVb's possible role in the evolution of cannabis chemotypes.

I only use it durring flowering and as I stated it DOES NOT increase globular capitate production just quickens THC formation and then degradation. I have seen an increase in stalked capitate production, much to my surprise, doing that experiment last summer, on 3 of 5 strains tested.(using UVb from the beginning of veggative growth)

BTW; I will exploit my "wards" every way posible (thru temps, light spectrums, co2 levels, etc) to create a better finished product in the fastest way possible.

Sorry that your "results" have been incosequential. Some other time we can debate what a commited grower is, I've only been at this for a "few" years.

OM

 

[big twinn]

Hmmm this thread is WAY more useful than i originally thought! Thanks for everyones contributions! Info regarding UVB is very scattered and sparse so having everything in one place sure is nice and useful!

I'm starting to think that the reptile lamps were a waste as far as 78 bucks goes. luckily they have ZERO places to mount it from above (they generally aernt mounted in reptile aquariums, rather they are held on top by the screen top on the cage) so since i have been a pit perplexed as far as mounting, i prob. will end up return them in favor of a better supplemental lighting system.

Whats your guys' thoughts on actinic lighting...pretty much the same for reptile lighting?
I have a 250HPS in my cab, which is pushing it! temps are low 80s high 70s and many people thought this light would be too much for my small space. (its a space more suitable for a 150HPS but i like the additional lumens

So given tight size restraints and temp. what would you all recommend if anything as far as supplemental lighting that will make the biggest positive impact. Or am i over killing it.
Not sure if i have the space for a CMH unfortunately.

 

[growshopfrank]

marijuana man thc uvb and me

http://www.youtube.com/watch?v=lfiI78uN3Ks

 

[Oldmac]

Hey growshopfrank,

Thank you for posting that video, while I don't ususally use youtube video's as a source of info (I've seen way too many LED one's that were more diesigned to trap the unsuspecting) that one was really good.

It seemed to mirror what I was saying, tho it made me look back at something I said. I shouldn't have placed CBN with CBG the degradation product. CBN is actually a precursor of CBG, and I'd likr to correct that, and apologize for the mistake.

Only excuse is an old man working from memory....and my memory is starting to fail.

OM

 

[prune]

Hello prune and welcome to the boards,

You are correct that UVb is a powerfull oxidizer... it is used for disenfecting, along with UVc that is even more powerfull.

THC and it's precursors are very UVb receptive. The membrane located between the stalk and the globular section is where that magic happens. The very shape of the globular capitate is designed by nature to take light from any angle and focus it on that membrane, producing THC (cloudy condition) and more will start to create CBD/CBN (amber condition) which is a degradation product of THC. Over exposure for long enough periods will completely destroy the globular capitate (as Weezard points out) and that's not good. But it will increase the production of THC and will also accelerate it's break down.

I base my opinion on not just on my own experiments but also on scientific white papers. Here's one that explains UVb's possible role in the evolution of cannabis chemotypes.

I only use it durring flowering and as I stated it DOES NOT increase globular capitate production just quickens THC formation and then degradation. I have seen an increase in stalked capitate production, much to my surprise, doing that experiment last summer, on 3 of 5 strains tested.(using UVb from the beginning of veggative growth)

BTW; I will exploit my "wards" every way posible (thru temps, light spectrums, co2 levels, etc) to create a better finished product in the fastest way possible.

Sorry that your "results" have been incosequential. Some other time we can debate what a commited grower is, I've only been at this for a "few" years.

OM

Ok, i read the pdf and in all honesty it was only a Proposed Hypothetical Model , which is really not much more than what we do here... lol
I would also mention that as a "White Paper", it was somewhat yellowed, and did not seem to be aware of recent (last decade or two) advancements in DNA analysis, historical discoveries, and THC variants. (things i read about)


Other than that, the real argument here is not chicken/egg, it's results. My preferred result is the fresh, light, engaging effect typical of low CBD content, and by limiting oxidative stress (UVB, heat, etc) during flowering, my bud has "legs" in the jar. If i want a heavier effect i can just leave it in the jar longer, my choice! If it is supplied already dialed in as "couchlock", there is no going back...

BWDIK, i've only been doing this a "few" decades, so don't listen to me...

 

[messn'n'gommin']

Ok, i read the pdf and in all honesty it was only a Proposed Hypothetical Model , which is really not much more than what we do here... lol
I would also mention that as a "White Paper", it was somewhat yellowed, and did not seem to be aware of recent (last decade or two) advancements in DNA analysis, historical discoveries, and THC variants. (things i read about)


Other than that, the real argument here is not chicken/egg, it's results. My preferred result is the fresh, light, engaging effect typical of low CBD content, and by limiting oxidative stress (UVB, heat, etc) during flowering, my bud has "legs" in the jar. If i want a heavier effect i can just leave it in the jar longer, my choice! If it is supplied already dialed in as "couchlock", there is no going back...

BWDIK, i've only been doing this a "few" decades, so don't listen to me...

Would really like to read some of the studies you spoke of. Could you throw up a few links? Thanks!

 

[Oldmac]

Dear prune, I really can't believe you want to go down this road.......

Ok, i read the pdf and in all honesty it was only a Proposed Hypothetical Model , which is really not much more than what we do here... lol
....of the Evolution. Sorry most of my current papers are in my old computer. The hypothetical model is the evolution part, that UVb influences the plant is a given.
I would also mention that as a "White Paper", it was somewhat yellowed, and did not seem to be aware of recent (last decade or two) advancements in DNA analysis, historical discoveries, and THC variants. (things i read about)
You are correct, it is an older paper....for some old and newer papers that deal with UVb and it's importance in the manufacturing of THC and cannabinoids google R. Mechoulam who is deemed the "grandfather of THC/cannabiniod research". But with that all said the paper indicates that UVb is responsible for the formation of certian chemicals, such as THC. Oh.....and makes no mention of UVb's oxitive properties....hmmmm.

Other than that, the real argument here is not chicken/egg, it's results. My preferred result is the fresh, light, engaging effect typical of low CBD content, and by limiting oxidative stress (UVB, heat, etc) during flowering, my bud has "legs" in the jar.
NO this is not chicken/egg....it's about you insisting that the only roll of UVb is it's "oxidative stress" which is wrong, without some form of blue and below light and preferablly UVb you won't make THC and/or not in a timely manner. I do a White Rhino to 25-50% amber for cancer patients and patients in hospice care, for it's narcotic effect and done that way on purpose. When a patient needs "a light, engaging effect...." I provide them with PPP done in a completely manner for that. Legs my hairy ass. I have also been growing the heck out of a strain nicknamed "apricot" that would not interest you, it will only give you a mild stone and no matter how much you vape/smoke you don't get any higher. But it stimulates appetite, surpresses nausea and is moderately pain relieving. Excellent for cancer patients undergoing treatments.
BTW, I provide to both a cancer support group and a hospice care organization medical marijuanna free of charge. I even loan patients vaporizers and show them how to effectively medicate.
If i want a heavier effect i can just leave it in the jar longer, my choice!
If you are managing to turn trichomes from cloudy to amber you must be keeping your jars in the sun. What curring does is break down more of the clorophyl compounds and increase flavornoids to make the mj vape/smoke smoother. It does not get "stronger".... you got what you got. Tho maybe you have some scientific proof this occurs?
If it is supplied already dialed in as "couchlock", there is no going back...
You don't seem to understand the concept of personal choice involved here, I feel sorry for you....it's considered grower's choice. I won't tell you what to look for in your recreactional drugs and don't you even begin to tell me what I should be growing for my patients.

BWDIK, i've only been doing this a "few" decades, so don't listen to me...
[I was just being modest....and trying to bait a troll....I think I caught a big one. Not only does he not realize I'm old but that I am also cranky]
First, it would be nice if you had some facts to support your positon(s). Growshopfrank posted a video that pretty much lays out the process that makes THC, the same process I laid out in the above posts.
Second, I'll have you know that I've been growing cannabis in one form or another for over SEVENTY YEARS. I started on a tobacco farm in 1940 at the age of 10 we grew 2 types of hemp; a tall, lanky Indian sativa used for fiber and a short, bushy Russian ruderalis used to produce oil from it's seeds. Also the Puerto Rican farm workers grew this female only seedless wildwood weed. By 11 I could identify plant sex, recognize pollen drop and help do something about it. About this time a doctor suggested that I smoke corn tassles and wildwood flower to help with my asthma. Considered it a medicine ever since, long before any state medical laws.
Marijuanna has been a life long interest of mine and I have had the good fortune to be able to work around the world and managed to collect many landrace sativa's and a few indica's. My seed bank seemed to become very valuable during the '80's as more and more breeder's sought landrace strain's to breed off of.
Just a few years back I took some college courses in horticulure to learn more about plant physiology so that I could exploit the plant further. I also learned some great things about light spectrums and how to make those work to produce plants with tighter node spacing and the adding of bio-mass to a plant. As it says in my signature,"the more you know...the better you'll grow". I live my life by some simple rules, such as try to learn something new everyday. Today I learned that I can't tolerate fools like I used to.

Please try to make your post #3 better by adding to an intelligent conversation by trying to provide some documention or references or just go back under the bridge.

OM

 

[Phaeton]

I noticed those older dates in the paper also, but I considered the source and concluded relevance was still applicable.

In fact I have six 2' reptile lights enroute as of this morning.
I had hoped a naked 300 watt halogen would also put out some UVB. It does, like .2 of 1%, that is 99.998 percent non UV, mostly red and infrared, not what I was after at all.

What made my mind up is the time saving. Oldmac showed no increase in trichome # but the control number was reached over a week earlier. I'm willing to invest a few dollars to see what happens with my strain, realizing all things are never equal.