How much UVB to give.

Bookush34

Well-Known Member
I am looking at adding a UBV light to my grow. I’ve done some research and am pretty convinced it should increase THC production.
One thing I could not find a consistent answer on is how much UVB to give and how many hrs on and off.

I am thinking of going with solarcure’s 2ft flower power setup.
Their site says max 1 hr a day. But have seen posts of people using it for the full 12hr lights on and many different increments in between.

what do you guys recommend and what are your results with using UVB
 

jimihendrix1

Well-Known Member
Using UV lamps as augmentation

This is the simplest way to use UV lights and creates the least amount of risk. Using one lamp for every 4 to 8 plants and running them for 2 to 3 hours per day, after a break in period to get the plants used to the new source of stress. This is to just simulate what they would normally get if they were grown in northern latitudes. UV effects are cumulative, so running higher power for shorter periods like this is very similar to having lower UV all day long.

Using UV lamps as plant stressing lights

This is trickier, but offers the greatest return. The goal is to push the limit of how much the plant can handle, up to the point before noticeable damage. This forces the plant into maximum protection mode and is done the last month of fruiting. Instead of producing larger fruit, it focuses on protecting the fruits already on the plant by producing much more resinous material (flavonoids or cannabinoids, depending on plant). What you end up with is denser but slightly smaller fruit that is considerably more potent. Some lab tests have indicated as much as 35% higher THC level in cannabis, although 20-25% is more realistic until the technique is mastered over a few seasons.

When it comes to cannabis, there is no single guide on how to do this, and never will be. This is because cannabis sativa and cannabis indica are two very different strains with different tolerances, and most plants are hybrids. Sativa plants grow in areas that traditionally get more UV (and tend to naturally have more THC) whereas indica plants have been grown traditionally at higher latitudes and are higher in CBD than sativas. It short, it requires a hands on approach and careful monitoring for every hybrid. This is also true of non-cannabis plants, which are just as varied, just as much hybrids. If you are growing tomatoes in a greenhouse, this same principle would apply to you: You can't compare a Beefstake with a Roma when it comes to UV tolerance, you have to dial it in manually.

We use ours 6-8 hours a day from Seedlings -Flowering. We keep it off of rooting clones.
 

Doug Dawson

Well-Known Member
Using UV lamps as augmentation

This is the simplest way to use UV lights and creates the least amount of risk. Using one lamp for every 4 to 8 plants and running them for 2 to 3 hours per day, after a break in period to get the plants used to the new source of stress. This is to just simulate what they would normally get if they were grown in northern latitudes. UV effects are cumulative, so running higher power for shorter periods like this is very similar to having lower UV all day long.

Using UV lamps as plant stressing lights

This is trickier, but offers the greatest return. The goal is to push the limit of how much the plant can handle, up to the point before noticeable damage. This forces the plant into maximum protection mode and is done the last month of fruiting. Instead of producing larger fruit, it focuses on protecting the fruits already on the plant by producing much more resinous material (flavonoids or cannabinoids, depending on plant). What you end up with is denser but slightly smaller fruit that is considerably more potent. Some lab tests have indicated as much as 35% higher THC level in cannabis, although 20-25% is more realistic until the technique is mastered over a few seasons.

When it comes to cannabis, there is no single guide on how to do this, and never will be. This is because cannabis sativa and cannabis indica are two very different strains with different tolerances, and most plants are hybrids. Sativa plants grow in areas that traditionally get more UV (and tend to naturally have more THC) whereas indica plants have been grown traditionally at higher latitudes and are higher in CBD than sativas. It short, it requires a hands on approach and careful monitoring for every hybrid. This is also true of non-cannabis plants, which are just as varied, just as much hybrids. If you are growing tomatoes in a greenhouse, this same principle would apply to you: You can't compare a Beefstake with a Roma when it comes to UV tolerance, you have to dial it in manually.
It also depends a great deal on what light you use. UVA is most common in nature and the least harmful. UVB is much less common as most of it is absorbed before it reaches earth. UVC is harmful and should only be used for disinfecting, not for growing. Than it depends on the wattage. My HLG 600 light bar attachment is 30 watts and meant to run 12 hours during flower. I would not try that with a UVB setup, it would fry the plants. I agree, it really does require some hands on and experimentation.
 

jimihendrix1

Well-Known Member
Those Solacure lights are specifically made for plants. Been using them 4 years.

We use 2 of the 4ft x 32w in a 4 x 4 area, at 24 inches, and either a 1000w HID/Hortilux HPS, or a Gavita 1700e. I use 3 of them with a Gavita 1150w DE HID in a 4 x 5 area at 40 inches, and run them 8 hours because of the height difference.
Solacure is the most powerful UVA/B bulbs made for 280nm-305nm


How does the ultraviolet absorption of proteins impact analysis?
Ultraviolet absorption spectroscopy of proteins.

Amino Acids
Commonly, the optical absorption of proteins is measured at 280 nm. At this wavelength, the absorption of proteins is mainly due to the amino acids tryptophan, tyrosine and cysteine with their molar absorption coefficients decreasing in that order. Of course, the molar absorption coefficient of the protein itself at 280 nm will depend upon the relative concentrations of each of these three amino acids. Therefore, different proteins can have different absorption coefficients and even the wavelength of the maximum absorption may differ. This fact can be used to help identify different types of proteins by relatively fast and simple optical tests.
Imaging Proteins by UV Absorbance
Most commonly, protein crystals are imaged by their intrinsic protein fluorescence. This is mostly the fluorescence of tryptophan. As such, protein fluorescence requires very powerful UV light sources and very sensitive cameras because the fluorescent emission from proteins is so weak. However, powerful UV light sources can destroy the protein due to long exposure times required to obtain significant data.
A much faster way to image proteins, either in cells, tissues or as crystals, is to utilize their strong absorption of UV light as a contrasting mechanism. By using a ultraviolet microscope or microspectrophotometer equipped for UV imaging, the sample containing the protein is imaged with 280 nm light. The protein will absorb this light more strongly than the surrounding sample and will appear darker. See the picture above for an example of UV absorption of a protein crystal in salt solution. This technique is very fast, exposing the protein to UV light for far less time.
Spectroscopy of Proteins by UV Absorption
CRAIC Technologies microspectrophotometers are used to acquire spectra of microscopic samples containing proteins, such as individual protein crystals, by their UV absorption. The microspectrophotometer consists of a UV-visible-NIR range microscope integrated with a spectrophotometer. As such, it is able to measure the UV-visible-NIR spectra of microscopic samples of tissue, protein crystals and other protein containing structures. By using absorption, it is able to measure these samples quickly and non-destructively.
Microspectroscopy allows the user to learn more about the optical features and the chemical structure of the protein. Additionally, microspectroscopy also allows for the determination of the concentration of protein in a sample as the absorption at 280 nm is proportional to the protein concentration.
If the protein sample does not have tryptophan or tyrosine, both of which absorb at 280 nm, the concentration can still be easily measured by the Scopes Method. In this particular method, the protein concentration is determined by the absorption at 205 nm in which the peptide bonds are analyzed directly.
DNA or RNA purity can also be determined by measuring the absorption ratios of 260 to 280 nm. This is because the nucleic acids that make up DNA and RNA absorb strongly at 260 nm. A ratio of about 2.0 is considered "pure" for RNA while a ratio of about 1.8 is considered "pure" for DNA. Lower ratios indicate the presence of protein.
Summary
Proteins absorb strongly at 280 nm due to three types of its constituent amino acids. The peptide bonds found in the amino acids also absorb at 205 nm. The UV absorption of protein can be used both to quickly image and acquire spectra of microscopic samples non-destructively. The spectra can also be used to determine protein concentrations and the relative amounts of protein to DNA or RNA.
 
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Doug Dawson

Well-Known Member
Those Solacure lights are specifically made for plants. Been using them 4 years.

We use 2 of the 4ft x 32w in a 4 x 4 area, at 24 inches, and either a 1000w HID/Hortilux HPS, or a Gavita 1700e. I use 3 of them with a Gavita 1150w DE HID in a 4 x 5 area at 40 inches, and run them 8 hours because of the height difference.
If you have been running those specific lights than you know more than I about them. I am really talking about UV in general and it's effects. My HLG light addon bolts to my existing 600 and is meant to run full 12/12 cycle. I can't speak to the others.
 

jimihendrix1

Well-Known Member
They will FRY your plants if they are to close, and/or left on to long. They can also be extremely damaging to your eyes, and unless I have to, I never go in with those on. They arent in use all the time, so I time my visits accordingly. I usually have the normal lights come on for 3 hours before the UVA/B lights come on, and 3 hours before 12 hours is up, they go off, unless its the 1150w Gavita. Lights come on 2 hours after the Gavita comes on, and go off 2 hours before Gavita goes off.
 

Cabrone

Active Member
Migro has new T8-Uvb reflector fixtures out. $75.
I believe his recommendation was 2 hrs a day at mid day.
 

Doug Dawson

Well-Known Member
Migro has new T8-Uvb reflector fixtures out. $75.
I believe his recommendation was 2 hrs a day at mid day.
That one is 75% uvb, yes short bursts for that specific light.
 

jimihendrix1

Well-Known Member
That one is 75% uvb, yes short bursts for that specific light.
But that light is only 310nm

Marijuana has a gene that is triggered at 280nm. Solacure is only bulb on the market that has its most power spectrum from 280nm-305nm. It takes special, really expensive glass to be able to go down to 280nm.


All UVB lamps are pretty much the same

Very wrong for a variety of reasons. For starters, UVB isn't a singular thing. It is a range of colors that span 280nm to 320nm. Virtually all UVB bulbs only produce only the lower energy portion of that spectrum, 300-320nm. The Flower Power is the exception, because it uses a patented glass. The higher bands from 280-290nm in particular are exponentially more powerful and where you get a real defense reaction from the plant.

As long as you give it some kind of UVB, you are going to get the same results

Basic plant biology says otherwise. The protein that tells cannabis (and other plants) that they are in a high UVB environment is called UVR8. Triggering this protein is what makes the plant go into overdrive and produce tons of extra trichomes. The only way this is triggered is by exposure to 280-290nm. The overwhelming majority of UVB lamps do not produce this range.
 

Doug Dawson

Well-Known Member
But that light is only 310nm

Marijuana has a gene that is triggered at 280nm. Solacure is only bulb on the market that has its most power spectrum from 280nm-305nm. It takes special, really expensive glass to be able to go down to 280nm.


All UVB lamps are pretty much the same

Very wrong for a variety of reasons. For starters, UVB isn't a singular thing. It is a range of colors that span 280nm to 320nm. Virtually all UVB bulbs only produce only the lower energy portion of that spectrum, 300-320nm. The Flower Power is the exception, because it uses a patented glass. The higher bands from 280-290nm in particular are exponentially more powerful and where you get a real defense reaction from the plant.

As long as you give it some kind of UVB, you are going to get the same results

Basic plant biology says otherwise. The protein that tells cannabis (and other plants) that they are in a high UVB environment is called UVR8. Triggering this protein is what makes the plant go into overdrive and produce tons of extra trichomes. The only way this is triggered is by exposure to 280-290nm. The overwhelming majority of UVB lamps do not produce this range.
I don't totally agree with what you are saying. Yes the lower bands of UVB are more effective and they are also the most harmful. They must be used very sparingly because although they shock the plant into producing trichomes for protection it does not totally protect the plant and UVB gets in. Because UV-B can damage the plant’s cells, this can lead to stress—which will ultimately cause lower yields but more potent buds. UVA also triggers this defence, it is just less harmful and thus not as potent for the job. There is no question low band UVB 280 - 290nm is the most effective but also the most dangerous. There is no doubt that not all UVB lamps are the same, there is always a range on the market and true UVB are very expensive.
 

jimihendrix1

Well-Known Member
Its not me saying it. Its science. Aint my opinion. I cant express an opinion it on a technical level, Im going by studies they did at Perdue University, and numerous other studies both in colleges, and going all the way back to the 70s in Skylab. Remember Skylab??????.......Marijuana was the first plant they grew in space, and experimented with different light wave lengths. The one I read the article on used the light Xenon, and millions of lumens, and only flashed for milliseconds. But they proved back in the 70s that cannabinoids could be influenced by manipulating the different light waves.

Science know marijuana has a protein thats triggers at 280nm. Thats a scientific fact.

This is not my opinion.

The protein that tells cannabis (and other plants) that they are in a high UVB environment is called UVR8. Triggering this protein is what makes the plant go into overdrive and produce tons of extra trichomes. The only way this is triggered is by exposure to 280-290nm. The overwhelming majority of UVB lamps do not produce this range.




UVR8
From Wikipedia, the free encyclopedia



Jump to navigationJump to search
Other data
Identifiers
UVB-resistance protein UVR8
4dnw.png
Crystal structure of UVB-resistance protein UVR8.[1]
OrganismArabidopsis thaliana
SymbolUVR8
Entrez836506
PDB4DNW More structures
RefSeq (mRNA)NM_125781
RefSeq (Prot)NP_201191
UniProtQ9XHD7
Chromosome5: 25.55 - 25.56 Mb
showSearch for
UV-B resistance 8 (UVR8) also known as ultraviolet-B receptor UVR8 is an UV-Bsensing protein found in plants and possibly other sources.[2] It is responsible for sensing ultraviolet light in the range 280-315 nm and initiating the plant stress response. It is most sensitive at 285nm, near the lower limit of UVB. UVR8 was first identified as a crucial mediator of a plant's response to UV-B in Arabidopsis thaliana containing a mutation in this protein. This plant was found to have a hypersensitivity to UV-B[3] which damages DNA. UVR8 is thought to be a unique photoreceptor as it doesn't contain a prosthetic chromophore but its light-sensing ability is intrinsic to the molecule.[4] Tryptophan (Trp) residue 285 has been suggested to act the UV-B sensor, while other Trp residues have been also seen to be involved (Trp233 > Trp337 > Trp94) although in-vivo data suggests that Trp285 and Trp233 are most important.[2]


Evolution[edit]
Although the complete genome sequence is only available from a limited number of angiosperms, bioinformatic analysis suggests that there are a large number of UVR8 orthologs. Both number and position of key residues seem to be well conserved among angiosperms but also other plant species (e.g., Chlamydomonas reinhardtii and Volvox carteri). The latter implies that UVR8 potentially appeared before the evolutionary split in vascular land plants which would be rational considering that at that time the amount of UV-B radiation that penetrated the earth surface was higher as the ozone layer was not fully developed, hence UV protection and acclimation would be of crucial importance.[5]
Structure[edit]
UVR8 is a β-propeller protein with 7 blade-shaped β-sheets. It shares sequence homology with mammalian proteins involved in regulating chromatin condensation, for example the human RCC1 gene product. In the dark state, UVR8 forms a homodimer that is localized in the cytosol, but UV-B illumination induces the dissociation of UVR8 dimer to its respective monomers and translocation to the nucleus occurs.[6] The dimer is held together via a complex salt bridge network.[2]
Mechanism[edit]
Upon UV-B irradiation, light is absorbed by one or more Trp residues which are situated adjacent to Arg residues which form salt bridges across the dimer interface. It is thought that this light absorption induces the disruption of the salt-bridges and thus leads to the molecule's monomerization.[2][7] Following monomerization, UVR8 accumulates in the nucleus where it interacts with a protein called constitutively photomorphogenic 1 (COP1). COP1 is known to act as an E3 Ubiquitin ligase that targets key transcription factors for ubiquitination and proteasome-mediated degradation. However, in the case of UVR8, it has been shown to act as a positive regulator of UVR8-mediated UV-B signalling.[8] Upon UV-B illumination, UVR8 interacts via a C-terminal 27 amino acid region with the WD40 domain of COP1 in the nucleus,[9] which triggers the induction of ELONGATED HYPOCOTYL 5 (HY5) — a key transcription factor for several UV-B responsive genes, and overall results in UV-B acclimation.[10]
 

Doug Dawson

Well-Known Member
Its not me saying it. Its science. Aint my opinion. I cant express an opinion it on a technical level, Im going by studies they did at Perdue University, and numerous other studies both in colleges, and going all the way back to the 70s in Skylab. Remember Skylab??????.......Marijuana was the first plant they grew in space, and experimented with different light wave lengths. The one I read the article on used the light Xenon, and millions of lumens, and only flashed for milliseconds. But they proved back in the 70s that cannabinoids could be influenced by manipulating the different light waves.

Science know marijuana has a protein thats triggers at 280nm. Thats a scientific fact.

This is not my opinion.

The protein that tells cannabis (and other plants) that they are in a high UVB environment is called UVR8. Triggering this protein is what makes the plant go into overdrive and produce tons of extra trichomes. The only way this is triggered is by exposure to 280-290nm. The overwhelming majority of UVB lamps do not produce this range.




UVR8
From Wikipedia, the free encyclopedia



Jump to navigationJump to search
UVB-resistance protein UVR8
Identifiers
Other data
4dnw.png
Crystal structure of UVB-resistance protein UVR8.[1]
OrganismArabidopsis thaliana
SymbolUVR8
Entrez836506
PDB4DNW More structures
RefSeq (mRNA)NM_125781
RefSeq (Prot)NP_201191
UniProtQ9XHD7
Chromosome5: 25.55 - 25.56 Mb
showSearch for
UV-B resistance 8 (UVR8) also known as ultraviolet-B receptor UVR8 is an UV-Bsensingprotein found in plants and possibly other sources.[2] It is responsible for sensing ultraviolet light in the range 280-315 nm and initiating the plant stress response. It is most sensitive at 285nm, near the lower limit of UVB. UVR8 was first identified as a crucial mediator of a plant's response to UV-B in Arabidopsis thaliana containing a mutation in this protein. This plant was found to have a hypersensitivity to UV-B[3] which damages DNA. UVR8 is thought to be a unique photoreceptor as it doesn't contain a prosthetic chromophore but its light-sensing ability is intrinsic to the molecule.[4]Tryptophan (Trp) residue 285 has been suggested to act the UV-B sensor, while other Trp residues have been also seen to be involved (Trp233 > Trp337 > Trp94) although in-vivo data suggests that Trp285 and Trp233 are most important.[2]



Evolution[edit]
Although the complete genome sequence is only available from a limited number of angiosperms, bioinformatic analysis suggests that there are a large number of UVR8 orthologs. Both number and position of key residues seem to be well conserved among angiosperms but also other plant species (e.g., Chlamydomonas reinhardtii and Volvox carteri). The latter implies that UVR8 potentially appeared before the evolutionary split in vascular land plants which would be rational considering that at that time the amount of UV-B radiation that penetrated the earth surface was higher as the ozone layer was not fully developed, hence UV protection and acclimation would be of crucial importance.[5]
Structure[edit]
UVR8 is a β-propeller protein with 7 blade-shaped β-sheets. It shares sequence homology with mammalian proteins involved in regulating chromatin condensation, for example the human RCC1 gene product. In the dark state, UVR8 forms a homodimer that is localized in the cytosol, but UV-B illumination induces the dissociation of UVR8 dimer to its respective monomers and translocation to the nucleus occurs.[6] The dimer is held together via a complex salt bridge network.[2]
Mechanism[edit]
Upon UV-B irradiation, light is absorbed by one or more Trp residues which are situated adjacent to Arg residues which form salt bridges across the dimer interface. It is thought that this light absorption induces the disruption of the salt-bridges and thus leads to the molecule's monomerization.[2][7] Following monomerization, UVR8 accumulates in the nucleus where it interacts with a protein called constitutively photomorphogenic 1 (COP1). COP1 is known to act as an E3 Ubiquitin ligase that targets key transcription factors for ubiquitination and proteasome-mediated degradation. However, in the case of UVR8, it has been shown to act as a positive regulator of UVR8-mediated UV-B signalling.[8] Upon UV-B illumination, UVR8 interacts via a C-terminal 27 amino acid region with the WD40 domain of COP1 in the nucleus,[9] which triggers the induction of ELONGATED HYPOCOTYL 5 (HY5) — a key transcription factor for several UV-B responsive genes, and overall results in UV-B acclimation.[10]
Ok got it. You are saying all UV lights are useless for pot unless it is 280-290nm and that only a light at 280-290nm is effective. So basically 99 % plus of the UV lights out there do nothing for your grow. Give this a read bud. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6455078/
 

jimihendrix1

Well-Known Member
Ok got it. You are saying all UV lights are useless for pot unless it is 280-290nm and that only a light at 280-290nm is effective. So basically 99 % plus of the UV lights out there do nothing for your grow. Give this a read bud. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6455078/

Im not saying it sir. SCIENCE says the Protein Receptor UVR8, which causes stress to the plant is only activated at 280nm-305nm. Take it for whatever you wish.

Not my opinion. Its plant physiology. Scientific fact.

So yes, to INCREASE THC if the light is not in the 280nm-305 range, its useless. The plant needs all forms of UVA/B as it evolved with it, but the UVR8 Protein is triggered at 280nm-285nm - 305nm. No getting around it.
It also takes special glass to transmit this wavelength.



UV-B resistance 8 (UVR8) also known as ultraviolet-B receptor UVR8 is an UV-Bsensing protein found in plants and possibly other sources.[2] It is responsible for sensing ultraviolet light in the range 280-315 nm and initiating the plant stress response. It is most sensitive at 285nm, near the lower limit of UVB.
 

GrassBurner

Well-Known Member
Right now flower is running 12-12. So I've got them on from 2-3, 4-5, and 6-7. Running hybrids. Ive got some heavy leaning sativa's ill be running soon, and those will probably get about 5 hours of UV light.
 

Bookush34

Well-Known Member
Ive been running a 4' solacure in my 2x4 for a couple of months now, upon recommendation from @jimihendrix1 I love it, used it the last 4 or 5 weeks of flower on my last harvest, had super frosty buds.
So far so good, nice light, and I got the mini fixture. Slim and narrow, nice for mounting in tight spots.
What kinda light schedule are you running them on
 
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