UV Suppliment Lighting

CannaOnerStar

CannaOnerStar

Well-Known Member
UpstateRecGrower said:
I never really got into far red, ive stumbled across threads a few times, what does it change?
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Common idea used to be that its not good for the plants, but i have read newer stuff that says that it actually bulks up the buds and is the reason why HPS light is good at making fat buds. Im sure people will debate on this, i dont claim to know the truth for certain, but i am leaning that on the side that far red is good for the plant. Ofc too much is too much and too far red would not help and would only be heat.
 
Kassiopeija

Kassiopeija

Well-Known Member
UpstateRecGrower said:
I never really got into far red, ive stumbled across threads a few times, what does it change?
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a number of things... as End of Day treatment its putting the plants into respiration immediately so you gain increased flowering hormone levels. or extra lighting time...
Plus you could supplement this radiation throughout the day and gain add. photosynthesis from rays that penetrate deep but may cause stretch. but your UV setup should prevent that to some extend ...

btw arent you afraid the UV damages the diodes?
 
nunyabidness420

nunyabidness420

Well-Known Member
I was running a mix of 285, 365, 395, and 420nm LEDs.
I used a spread just in case this whole UV thing turns out to be like the red/blue vs white light debate.

But if the UVR8 photo receptor is what we're trying to trigger for more THC production, would it be more efficient to run just the 285nm LEDs?
Seems to me this would trigger the plant's UV protection response without the rest of the wavelengths causing actual damage to the plant.
 
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Rocket Soul

Rocket Soul

Well-Known Member
nunyabidness420 said:
I was running a mix of 285, 365, 395, and 420nm LEDs.
I used a spread just in case this whole UV thing turns out to be like the red/blue vs white light debate.

But if the UVR8 photo receptor is what we're trying to trigger for more THC production, would it be more efficient to run just the 285nm LEDs?
Seems to me this would trigger the plant's UV protection response without the rest of the wavelengths causing actual damage to the plant.
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The theory ive heard around this is that the uva protects the plant from the uvb, adding only uvb could work as detrimental to the plant. Its hard to give uvb during the whole day without some burning.
 
nunyabidness420

nunyabidness420

Well-Known Member
Rocket Soul said:
The theory ive heard around this is that the uva protects the plant from the uvb, adding only uvb could work as detrimental to the plant. Its hard to give uvb during the whole day without some burning.
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I have no intention of being rude when I say this, its hard to convey tone on line, but is there a paper on this?
I've read of the "synergistic" effect of UVA, but "synergistic" is a marketing word isn't it?

I have't read every paper on UVR8 but this response curve seems to be pretty concrete as well as cut and dry.
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You can set your UV to turn on in short bursts during the course of your daily light cycle with one extra timer.
 
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Rocket Soul

Rocket Soul

Well-Known Member
nunyabidness420 said:
I have no intention of being rude when I say this, its hard to convey tone on line, but is there a paper on this?
I've read of the "synergistic" effect of UVA, but "synergistic" is a marketing word isn't it?

I have't read every paper on UVR8 but this response curve seems to be pretty concrete as well as cut and dry.
View attachment 4671263

You can set your UV to turn on in short bursts during the course of your daily light cycle with one extra timer.
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No, i dont have a paper for that, just what i heard and from the little ive seen around. Originally this was quoted to me by @Randomblame who is like a friggin encyclopedia. He had a go with the uvb flourecents that a lot have been using and burned the shit out of his cropp and attributed it to wrong balance between uvb and uva. But i cant say for myself. Also, some tests by people here on riu have shown that uva supplement and uvb supplement resulted in similar thc. I say throw all the uv (except uvc) that your plant can handle.

I was recently able to try the difference between the indoor, led/cmh version of our Gluetrap, and an outdoor grown version. The outdoor was night-and-day stronger than the indoor, i defo recommend use as much and as diverse uv as you can your plants
 
nunyabidness420

nunyabidness420

Well-Known Member
Rocket Soul said:
No, i dont have a paper for that, just what i heard and from the little ive seen around. Originally this was quoted to me by @Randomblame who is like a friggin encyclopedia. He had a go with the uvb flourecents that a lot have been using and burned the shit out of his cropp and attributed it to wrong balance between uvb and uva. But i cant say for myself. Also, some tests by people here on riu have shown that uva supplement and uvb supplement resulted in similar thc. I say throw all the uv (except uvc) that your plant can handle.

I was recently able to try the difference between the indoor, led/cmh version of our Gluetrap, and an outdoor grown version. The outdoor was night-and-day stronger than the indoor, i defo recommend use as much and as diverse uv as you can your plants
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Thank you, I'll put @Randomblame's posts on my reading list.
I've noticed more potency and more odor when I used the spread spectrum UV LED but there are still a lot of variables I have to account for and eliminate.
 
nunyabidness420

nunyabidness420

Well-Known Member
@salmonetin
agricultra was what convinced me to switch from reptile UV lamps to something with more 285nm wavelengths.
However their UV light originally started as 285+365nm and was later switch to 385nm while citing the same literature. :o
I haven't gone through all the research they cited on their page but the two (edit correction 3) I've read mention nothing about synergy.
Higher wavelength UV LEDs are cheaper and more efficient than lower wavelengths so I wonder why they made the switch if the literature didn't change.
 
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Warpedpassage

Warpedpassage

Well-Known Member
Randomblame said:
Below I've added a science paper the guys from SETi/SeoulViosys have made. They have used the latest research available and they have done own tests and have developed these SeoulViosys 285nm diodes we can get now from digikey.
In short, it's a 0,6w diode using 100mA at 6v and each diode produce 10mW/m². The output is pretty linear and with 150mA you would get almost 15mW. Maximum is 200mA but UVB diodes are very heat sensitive and I would not recommend to drive them that hard.

But lets make a quick calculation and lets say you have 6 of them and want to use them inside a 2x 4' tent with 0,72m². If you use a 3s2p circuit you could use a cheap 3$ ebay driver made for 5-7x 1w LED's. These diodes are expensive enough and you can buy 2 spare drivers if you want but they only run 1-2h per day so they will last at least a few runs. This drivers have 300mA but usually its more like 270 or 280mA. With 270mA each diode would get 135mA so in this case you would have at least 13mW x 6=78mW/s/m².

The recommended minimum UVB dose one need to get the desired results is around 360J/m²/day(see pdf). You can use more when the plants are used to it but of course only up to a certain point. To calculate J/m² we only have to multiply the output per sec. by the amount of seconds the light is switched on because 1J equals to 1W/s. So lets say you let it run for one hour you have to multiply 78 x 3600 (which is 60sec x 60mins) and get 280.800mJ or 280J and because its still for 1m² we need to divide it by 0,72m². So with this setup you could calculate having around 390J/m² in 1 hour inside your 2x4' area. So, who says one can not calculate the neccessary UVB dose? Its actually pretty simple to do that with LED's. Easier as with the bulbs...
With bulbs and 2-3' distance -or actually at any distance- you would need a UVB meter measuring the UVB radiation in mW at canopy level. Without these numbers its almost impossible to calculate how much you really have when using these bulbs. For this reason we Agromax pureUV owners have always to use the "try and error technique" to find the optimal dose for a certain hanging height.
In the late flowering stage I have the bulbs hanging only 12" above the canopy so that there is almost no UVB light hitting the walls but the 2' wide canopy is fully covered. With this short distance the bulbs run usually only 10-15mins before lights off and its more than enough. I always see heat stress and curled up leaf margins but its impossible to have the bulb behind my main fixture. It would block or reflect most of the light and almost nothing would reach down to the plants. 8-12inch is my optimal hanging height and using 6-8 of these diodes will make it much easier.

Its also not absolutely neccessary to combine them with UVA diodes because the self repair mechanism caused by certain UVA wavelengths also occur when plants are getting certain blue wavelengths. You can add 385nm diodes to trigger these mechanisms at several wavelengths and it may helps the plants to recover even better but you can just use white and UVB diodes without getting problems.
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Here is a great post by randomblame in which he mentions addition of uva in addition to uvb is unnecessary if there is adequate blue wavelength.
 
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Merlin1147

Merlin1147

Well-Known Member
nunyabidness420 said:
Thank you, I'll put @Randomblame's posts on my reading list.
I've noticed more potency and more odor when I used the spread spectrum UV LED but there are still a lot of variables I have to account for and eliminate.
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I’m running 390 up to 475 as an auxiliary supplemental light as well as UVB Arcadia 14%. As soon as I flip on that blue channel the smell in the tent go way up Even with a scrubber running. Turn it off and it goes right back down.
 
nunyabidness420

nunyabidness420

Well-Known Member
Merlin1147 said:
I’m running 390 up to 475 as an auxiliary supplemental light as well as UVB Arcadia 14%. As soon as I flip on that blue channel the smell in the tent go way up Even with a scrubber running. Turn it off and it goes right back down.
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I think 475nm is under used in LED light. Its still photo synthetically active and deficient in just about every white LED.
 
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