UV lights

Alistair

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Hey there,

Who knows about UV lights? Are they useful for growing, and why? What kind of setup to use, and where to buy it? How many watts to use per Sq. foot? How many watts, etc.?

Any suggestions would be appreciated,

Alistair
 

3patas

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Alistair Young said:
Hey there,

Who knows about UV lights? Are they useful for growing, and why? What kind of setup to use, and where to buy it? How many watts to use per Sq. foot? How many watts, etc.?

Any suggestions would be appreciated,

Alistair
uv lights are no good they are created for reptiles they produce more heat than lumens if you are on a buget you can start with cfl very cheap or if you have the money go for hps good luck and peace out
 

LaserKittensGoPewPew

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3patas said:
uv lights are no good they are created for reptiles they produce more heat than lumens if you are on a buget you can start with cfl very cheap or if you have the money go for hps good luck and peace out

Actually UV-B lights are good as supplemental lights to your regular flower lights. The reason being is that UV-B radiation increases the THC content in the budding flowers. If you use these as a supplement light your bud will definitely be more potent.

I've used these on my bigger grows and the buds were definitely much more sedative than the buds from previous grows that didn't have the UV-B lights. Not everyone likes the knock down stone though so it's your call.
 

3patas

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LaserKittensGoPewPew said:
Actually UV-B lights are good as supplemental lights to your regular flower lights. The reason being is that UV-B radiation increases the THC content in the budding flowers. If you use these as a supplement light your bud will definitely be more potent.

I've used these on my bigger grows and the buds were definitely much more sedative than the buds from previous grows that didn't have the UV-B lights. Not everyone likes the knock down stone though so it's your call.
for my understanding they were created to produce heat for lizzars, turtle,snakes, ect what for? well all reptiles need to heat up to power up so defenetly it will produce heat and heat and mj dont get along too well but that me everybody have theire op[inion good luck and peace out
 

KADE

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anyone that uses heat lamps are idiots... period. It is bad enough keeping 8 cfls in a cabinet cool let alone 8 - 1000w hps lamps.
 

bombbudpuffa

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anyone that uses heat lamps are idiots... period.
Some growers add a uv light in the later stages of flowering to increase resin production. UV increases resin production, it's actually one of the reasons MJ grows resin heads;). I've also seen people switch from HPS to MH later in flowering because MH gives off more UV than HPS. I wouldn't say they were idiots. I think it's a good theory.
 

Hick

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There are studies that indicate that UV rays do have positive effects on trichome production and potency.
If the reptile lights benefits equal their heat control issues, I can't say. But if they re beneficial, it would certainly be only as supplemental lighting, not as your primary light.
 

LaserKittensGoPewPew

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correct bombbud and hick. 2 guys who actually know what they're talking about.

Yes, UV reptile tubes put out a lot of heat. Obviously if you are going to use these as UV-B supplemental lights you need to be able to ventilate your grow space to offset the added heat. It's not the heat we're after. It's the UV-B spectrum that's important.

Lady M puts out resin heads in the first place as a natural defense against UV rays put out by the sun. UV-B can mutate/damage cells. There is a reason the resin is all over the buds. The calyx is where the seeds are created. And the seed is storing the genetic composition of the plant. This needs to be protected from those damaging UV rays so there are no mutations. This is why the plant coats itself in resin.
 

LaserKittensGoPewPew

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This is an article I found on icmag. Good read for those who are interested in UV-B for growing.

"Resin glands, and the uv light connection

here's an article i found. A few of us have talked about it on a few threads. An elaboration on the phytochemical process that makes marijuana THC
The resin exuded by the glandular trichome forms a sphere that encases the head cells.

When the resin spheres are separated from the dried plant material by electrostatic attraction and placed on a microscope slide illuminated with a 100W incandescent bulb, they appear very dark when observed through a 300X microscope. Since orange, red, and infrared are the component wavelengths of incandescent light, and since the absorption of light makes an object dark or opaque to the frequency of the incoming wave, one can conclude that these wavelengths are probably not directly involved in energizing the cannabinoid pathway.

However, the resin sphere is transparent to ultraviolet radiation.

The author found through trial and error that only one glandular
trichome exhibits the phytochemical process that will produce the amount of THC associated with pain relief, appetite stimulation and anti-nausea; euphoria and hallucinations are side-effects, however. This trichome is triggered into growth by either of the two ways that the floral bract is turned into fruit.

Of all the ways that optics are involved in the phytochemical production of THC, the most interesting has to be how the head cells and cannabinoid molecules are tremendously magnified by the resin sphere. These and other facts are curiously absent from the literature. The footnotes update the literature to include electrostatic separation of the resin sphere from the dried plant material and marijuana parthenocarpy.


(1) "For all spheres, a ray drawn perpendicular to the sphere's surface will intersect the center of the sphere, no matter what spot on the surface is picked, and the magnifying power(a) of a glass sphere is greater the smaller its size. A sphere of glass can also bring light that is heading to a focus behind it to a point within it, with freedom from two aberrations, spherial aberration and coma, but not from chromatic aberration. Chromatic aberration results when different wavelengths are focused on different planes and is the most difficult of the aberrations to correct. The human eye lens also exhibits chromatic aberration, but a yellow pigment(b) called the macula lutea in the fovea, an area at the rear of the eyeball, corrects this problem by the way it absorbs blue light."

(a)"The formula to calculate the magnifying power of a sphere is l=333/d, where l is the magnifying power and d is the diameter of the sphere expressed in mm."

(b)Interestingly, the resin exuded by drug-type flowering female marijuana plants has a yellow tint. Could this pigment work to correct chromatic aberration in the resin sphere like the macula lutea does in the fovea for the eyeball?

(2) Quoting from the Mahlberg and Kim study of hemp(a) "THC accumulated in abundance in the secretory cavity where it was associated with the following: cell walls, surface feature of secretory vesicles, fibrillar material released from disc cell wall, and cuticle. It was not associated with the content of the secretory vesicles."

The resin spheres contain the THC. It is not contained in the leaf or floral bract. After the resin spheres are dissolved in solvent or dislodged by electrostatic attraction, and a microscopic examination of the leaf or floral bract has revealed that only the glandular trichomes' stalks remain, no effect will be felt after smoking the dried plant material from which the resin spheres have been removed.

(3) The electrostatic collection of the resin spheres from dried marijuana plants with plenty of ripe seeds has been for hundreds of years the method indigenous people of North Africa and Lebanon have used to make hashish. Obtain a round metal can 8" or so in diameter x 3" or so in depth (the kind that cookies come in) with a smooth lid. Obtain 2 ounces of dried marijuana with plenty of ripe seeds in the tops. To remove the seeds and stems, sift the marijuana tops through a 10-hole-to-the-inch wire kitchen strainer into the can. Close the can with the lid and vigorously shake the closed can three or four times. This gives the resin spheres an excess negative charge. Let the can sit for a moment and then remove the lid. Opposites attract. The negative-charged resin spheres have been attracted to the metal surface of the can and lid which has a positive charge. Take a matchbook cover or credit card and draw the edge across the surface of the lid. Note the collected powder. Observed under 300X magnification, the collected powder from this "shake" is composed of resin spheres with an occasional non-glandular trichome. As the marijuana is shaken again and again, and more of the yellow resin spheres are removed from the plant material, the collected powder gradually becomes green-colored as the number of non-glandular trichomes increases in the collected powder. The greener the powder, the less the effect.

(4) "Cannabinoids represent a dimer consisting of a terpene and a phenol component. Cannabigerol (CBG) is the first component of the pathway. It undergoes chemical change to form either cannabichromene (CBC), or cannabidiol (CBD). Delta 9-tetrahydrocannabinol (THC) is derived from CBD."

(5) "Pate (1983) indicated that in areas of high ultraviolet radiation exposure, the UVB (280-320 nm) absorption properties of THC may have conferred an evolutionary advantage to Cannabis capable of greater production of this compound from biogenetic precursor CBD. The extent to which this production is also influenced by environmental UVB has also been experimentally determined by Lydon et al. (1987)."

The writer's own experience allow for a more specific conclusion: If the UVB photon is missing from the light stream(a), or the intensity as expressed in µW/cm2 falls below a certain level(b), the phytochemical process will not be completely energized with only UVA photons which are more penetrating but less energetic, and the harvested resin spheres will have mostly precursor compounds and not fully realized THC(c)."
 

LaserKittensGoPewPew

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Continued....

"(a)Examples of an environment where the UVB photon would be missing from the light stream include all indoor cultivation illuminated by HID bulbs and in glass or corrugated fiberglass covered greenhouses.

(b)"The maximum UVB irradiance near the equator (solar elevation angle less than 25 deg.) under clear, sunny skies is about 250 µW/cm2. It was observed that the daily solar UVB in Riyadh, Saudi Arabia (N24.4Lat.) decreased from September to December by about 40% (Hannan et al. 1984). The further a person is from the tropics, the less UVB radiation there is: the average annual exposure of a person living in Hawaii is approximately four times that of someone living in northern Europe." Below are some UVB readings taken in Hoyleton, Illinois, on a clear sunny day in June by David Krughoff as reported in Reptile Lighting 2000.

7am: 12 microwatts/cm2
8am: 74 microwatts/cm2
9am: 142 microwatts/cm2
10am: 192 microwatts/cm2
11am: 233 microwatts/cm2
12pm: 256 microwatts/cm2
1pm: 269 microwatts/cm2
2pm: 262 microwatts/cm2
3pm: 239 microwatts/cm2
4pm: 187 microwatts/cm2
5pm: 131 microwatts/cm2
6pm: 61 microwatts/cm2

(c)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."

(6) Capitate-stalked glandular trichome.

(7) #1: The ovum has been fertilized and there is a seed developing: In the areas of the Northern Hemisphere where indigenous people have grown heterozygous drug-type marijuana for hundreds of years, pollination is used to trigger the growth of the capitate-stalked glandular trichome on the floral bract and concomitant leaves of the flowering females before the autumnal equinox(a) so the majority of seeds will be ripe(b) before November.

(7) #2: The floral bract has become parthenocarpic: Parthenocarpic fruits develop without fertilization and have no seeds. Except for transmutation and turning lead into gold, there has been more nonsense written about seedless marijuana than on any other subject. In marijuana parthenocarpy, the floral bract (the fruit) enlarges in size as though there were a seed growing inside, and the capitate-stalked glandular trichome is triggered into growth on the floral bract and concomitant leaves. "Most popular supermarket tomatoes are parthenocarpic which was induced artificially by the application of dilute hormone sprays (such as auxins) to the flowers." In a trial, marijuana parthenocarpy was not induced by the application of the spray used on tomatoes. Only the photoperiod(c) will trigger parthenocarpy in flowering female marijuana plants. Marijuana parthenocarpy occurring before the autumnal equinox is considered by the author to be "long-day" and marijuana parthenocarpy occurring after the autumnal equinox to be "short-day".

The longest photoperiod that will trigger parthenocarpy in unfertilized flowering homozygous(d) Indica female marijuana plants is 13:00 hours, give or take 15 minutes. This effect can be obtained in the month of August at N35Lat, and because the capitate-stalked glandular trichomes received plenty of UVB during this month at this latitude, the harvested resin spheres had fully realized THC. Rating: euphoria and hallucinations, major appetite boost and pain relief, deep dreamless sleep. These plants seldom grow taller than four feet but potency makes up for the reduced harvest.

The gene pool is heterozygous if a flowering female marijuana plant is not parthenocarpic by the end of the first week in September in the Northern Hemisphere. If this is the case, pollination is used instead of parthenocarpy to trigger the growth of the capitate-stalked glandular trichome before the autumnal equinox to obtain as much fully realized THC as possible in the harvested resin spheres by the time the majority of the seeds are ripe.

The longest photoperiod that will trigger parthenocarpy in unfertilized flowering heterozygous female marijuana plants is 11:00 hours, give or take 15 minutes: This effect can be obtained in the month of November at N35Lat. Because of the low intensity of UVB radiation at this latitude at sea level during November, the harvested resin spheres evidenced only slightly more THC than precursor compounds. Rating: mild to medium euphoria, appetite boost and pain relief, good snooze.

Thai marijuana falls into this 11:00 hour category, and its parthenocarpy is characterized by an inflorescence in which many floral bracts are attached to an elongated meristem. It is these elongated meristems that are harvested to become a THAI STICK. On the other side of the world, Mexican marijuana grown around the same latitudes (Michoacan, Guerrero, Oaxaca) also falls into this short-day parthenocarpic category and the unfertilized marijuana will become "sensimilla" in the 11:00 hour photoperiod which begins in mid-December in that region. The winter sunshine in those latitudes has enough UVB intensity to produce fully realized THC--unlike the winter sunshine at N35Lat.

All unfertilized flowering female marijuana plants will become parthenocarpic in a 9:00 hour photoperiod (15:00 hour dark period): This can be obtained in the month of December at N35Lat. At this latitude in this month there is not even enough UVB in sunlight for precursor vitamin D3 to develop in human skin. The phytochemical process will not produce fully realized THC when UVB falls below a certain level of intensity expressed in µW/cm2. Rating: no effect.

(a)In the Northern Hemisphere above the Tropic of Cancer, the key to all marijuana potency is this: The more days of sunlight the capitate-stalked glandular trichomes' resin spheres accumulate before the autumnal equinox the more fully realized THC.

(b)It is recognized in the indigenous world that drug-type marijuana with a majority of ripe seeds will produce more euphoria, hallucinations, appetite stimulation, pain relief, and sleep aid than with a majority of unripe seeds.

(c)The photoperiodic response is controlled by phytochrome. "Phytochrome is a blue pigment in the leaves and seeds of plants and is found in 2 forms. One form is a blue form(Pfr), which absorbs red light, and the other is a blue-green form(Pr) that absorbs far-red light. Solar energy has 10X more red (660nm) than far-red (730nm) light causing the accumulation of Pfr." The first and last hour of a day's sunlight is mostly red light because of the scattering effect on blue light. "So at the onset of the dark period much of the phytochrome is in the Pfr form. However, Pfr is unstable and returns to phytochrome Pr in the dark." The red light in sunrise returns the Pr to the Pfr form. "Phytochrome Pfr is the active form and controls flowering and germination. It inhibits flowering of short-day plants (the long night period is required for the conversion of Pfr to Pr) and promotes flowering of long day plants."

(d)In Nepal and nearby areas of India where the capitate-stalked glandular trichome is triggered into growth by parthenocarpy rather than by fertilized ovum, great care is taken to make sure that all male marijuana plants are destroyed as soon as they reveal their sex. This is because unfertilized Indica flowering females can have both stigma and anther protruding from the floral bract. In the Indica gene pool, female-produced pollen carries an allele for long-day parthenocarpy, and seeds resulting from this female-produced pollen will produce another generation of female plants that will also exhibit long-day parthenocarpy during flowering. But if pollen from male plants is introduced into this gene pool, the resulting seeds will produce a generation of females that will exhibit short-day parthenocarpy instead. The allele for long-day parthenocarpy in the female-produced pollen is carried into the gene pool by self-pollination and cross-pollination, and perhaps homozygous is used too loosely here to describe the genetic result.

(8) It appears that the resin sphere acts as an UVB receptor and magnifying lens. The latter apparently lets it gather in a lot more photons than would otherwise be possible; because a lens also acts as a prism, the resin sphere may prevent some wavelengths from being focused where the phytochemical processes are taking place because they could interfere with the phytochemical process that makes THC.

electrostatic collection of resin spheres and non-glandular trichome."
 

massproducer

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KADE said:
anyone that uses heat lamps are idiots... period. It is bad enough keeping 8 cfls in a cabinet cool let alone 8 - 1000w hps lamps.

8 -1000w hps"s ? Where did this come from?
 

smokybear

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Lots of good information. Great info everyone. Take care and be safe.
 

Alistair

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Thanks to everyone for the information. The article is much appreciated for sure. Thanks PEW PEW.

I was looking at ceramic metal halide bulbs online. To me the bulbs look like HPS bulbs. What is a good brand of CMH bulb? You simply plug that into your socket with the HPS ballast? I use a switchable MH/HPS 400 watt ballast.

I've already noticed that the HPS bulb seems to be hotter than the metal halide bulb. Perhaps that's my imagination, I don't know. Is the CMH bulb any hotter than what I've already been using?

Thanks for the info,

Alistair
 

LaserKittensGoPewPew

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The CMH bulb will run cooler than the HPS. Some users have reported up to 10 degree drops in temperature in their grow rooms/cabs.

If you are using 0-150w you will need a Metal Halide ballast. If you are using 250-400w you will use a High Pressure Sodium ballast. With the switchable ballast you should be able to just put it on the HPS mode and run the 400w, but double check and make sure. That one I don't know about. Oh, and these don't work with digital ballasts so make sure it's a magnetic.

This is a link to the place where i bought mine. They also have a lot more literature on these bulbs if you look through all their product info stuff. Really great place and philips makes good quality stuff.

You'll see the comparison spectrum charts for the CMH and HPS... If you buy one just make sure you get the PROTECTED version. And I would say go with the 4000k instead of the 3000k. The 4000k puts out more spectrum.

http://advancedtechlighting.com/mhced17.htm
 

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