Anyone add UV light to LED Grow?

[DET—PDX]

Was reading an interesting article about how Marijuana is one of the subtropical species of plant which has adapted its own stress mechanism to UVB and UVA rays. I also am aware that most LEDs lack UV radiation, and even most metal halide lamps only emit about 10% of that wavelength. I am curious as to how one should add UV radiation to their grow if using LED’s?

I have heard of reptile lamps, but I have also read from another article that it makes sense to keep a UV light moving to avoid damaging plants. This could just be a company trying to sell their product, but it makes sense. UV Grow Lights with LightRail - Increase THC and Produce Faster That is the link.

Do you think there is truth to keeping UV light moving? And what do you see as the best supplemental UV light that can be added to an LED grow? I am still researching and haven’t found a whole lot on supplemental UV lighting, if anyone has any experience please comment below.

 

[PrometheanLeaf]

http://www.solacure.com/horticulture.html

Look under the horticultural section. Uv-b has quite a few lab tests to show that using it in small doses can increase THC levels quite a bit. Even finishing times seemed to decrease pretty regularly.

5-10% of total room wattage in 15 minutes increments between 2-4 hours daily. Is what I've seen the most success with. And I think Solacure does have the best bulbs. Followed by agromax pure uv, but the levels of uv-b are pretty intense when ran at this wattage. The most efficient, and cost effective, uv-b or uv-a will be in a florescent right now.

Not too much confirmed data on Uv-a though.

Even Stephen from HLG talked about implementing the Solacure UV-b bulbs to the hlg 550 himself, and as a possible future product for hlg over six months ago.

Edit: here is a cannabis specific page.
http://www.solacure.com/cannabis1.html

 

[HydroRed]

I used 4' T5's. AgroMax makes a bunch of different bulbs. There is one called "Pure UV" which gives off UV-A & UV-B. You have to be careful when running UV-B as it can cook your plants pretty quick. I opted for the 10K UV-A bulb since I didnt have to run it on its own timer. It didnt seem to make too much of a difference for me, but I dont have lab tests done on mine.

 

[SoMe_EfFin_MasS_HoLe]

Check out @Randomblame. He uses uv in his rig that he made. You could also consider him to be the led guru of all led guru'. Very smart, kind & extremely helpful gentleman.

 

[Randomblame]

I used 4' T5's. AgroMax makes a bunch of different bulbs. There is one called "Pure UV" which gives off UV-A & UV-B. You have to be careful when running UV-B as it can cook your plants pretty quick. I opted for the 10K UV-A bulb since I didnt have to run it on its own timer. It didnt seem to make too much of a difference for me, but I dont have lab tests done on mine.

Yeah, I've used reptile bulbs with 12% UVB and the spectrum chart of the 10k finisher looks almost identical.


I have them changed against PureUV bulbs and these bulbs need a min. distance of 24" to not harm the plants. I have 5 different strains below them and 2 of them are also more UVB sensitive. BlueDream, ColumbianGold and GreenPoison have shown no wilted leaves till now, Amnesia and SuperSilverHaze have shown heatstress and wiling leaves.



I've build so called super-spreaders. Do you remember them from the adjust-a-wing HPS reflectors? Its in fact just a 18mm small and 2ft long alu strips made from reflector sheet, bent by 90° along the length side. I've mount them in ~5mm distance in front of the bulbs so that the light hitting the spreader is thrown back into the reflector. This should reduce the readings in the center area and distribute the UV light more evenly.
I've also reduced their usage to 2x 30 minutes per day because I dont wanna loose the whole crop. I got also much less stretch as usual. BD, SSH and CG are known to stretch out for at least 4 weeks or more. This times they stopped stretching already end of week 2. I've added the trellis net too late because of this unexpected behavior and now I have a few gaps in the canopy. I've added more far-red from now on to get a little more stretch but maybe it's already too late. If you look closer you can see the most heatstress in the upper left corner on the Amnesia cross.


I have a minute timer and will try my best to find a way to use them at the same height with my LED's(I prefer ~16"); currently its still 24-28" above the canopy(UVB intensity should be below 170μW/cm² according to Agromax test results). If its impossible I'll switch back to reptile blubs cuz they are much less damaging and I've already used them with good results. My small 3sft area has a 24w Arcadia with 12% UVB and ~150w LED and I use both with only 8-10" distance and UVB for 5h every day(2x 2,5) and there in not a single damage and with such a low distance the UVB intensity is at least 150-200μW/cm² according to the test results with different types of reflectors(pdf below).
A little heatstress yes but no wilting leaves. It could be that the pureUV bulbs have already a few % UVC; the spectrum chart is unfortunately not exact enough to figure that out. But it could be a reason why these bulbs are too strong even if only used for a shorter period.
With reptile bulbs at 8" you already get 150μW/cm² for 5h that means you get a dose of 27kJ/m², with the 2x 30 minutes PureUV and 28" distance you would have less than 150μW/cm² and 1h means a dose of only 5,4kJ/m².
There must be a reason why these bulbs cause so much damage while the reptile/10k finisher bulbs cause no damage even after much longer use and same UVB intensity.
Apogee has a new UV sensor called UV-100 and the guy from Migro(youtube) is willing to do some spectrum tests and comparisions. So maybe will will know the reason pretty soon..

 

[Randomblame]

Was reading an interesting article about how Marijuana is one of the subtropical species of plant which has adapted its own stress mechanism to UVB and UVA rays. I also am aware that most LEDs lack UV radiation, and even most metal halide lamps only emit about 10% of that wavelength. I am curious as to how one should add UV radiation to their grow if using LED’s?

I have heard of reptile lamps, but I have also read from another article that it makes sense to keep a UV light moving to avoid damaging plants. This could just be a company trying to sell their product, but it makes sense. UV Grow Lights with LightRail - Increase THC and Produce Faster That is the link.

Do you think there is truth to keeping UV light moving? And what do you see as the best supplemental UV light that can be added to an LED grow? I am still researching and haven’t found a whole lot on supplemental UV lighting, if anyone has any experience please comment below.

The most easiest way to add these wavelength to your grow area are good reptile bulbs. The good ones have up to 14% and 30 UVA and they do not harm the plants. I can not say how these Flowerpower bulbs work but I can say, these Agromax PureUV are for sure too strong for beginners.
I've used reptile bulbs with good success and wanted to try these Agromax beasts but they are too strong to use them with less than 24" distance. Mine are currently 24-28" above the canopy(a 2ft bulb per 2x 2' area) and I have already wilting leaves with 3h per day. Its reduced to 1h per day now but I need to wait a few days to see if the wilting stops or not.

Thats especially strange cuz the intensity level is lower compared with the reptile bulbs which I've used with only 8-10" distance.

Could a light mover help to reduce the stress? Probably yes! Would be almost the same as when you use only short UVB pulses of 5 minutes but 12 times the day.
I'm just trying to figure out how to make good use of it. Maybe I have to go the pulsed way but for T5's its the worst case scenario. Such bulbs need a few minutes to warm up and stabilized their UV output and then they're already switched off?
That certainly accelerates aging..

Reptile bulbs (with 10-14%) or the Agromax 10k finisher I can recommend with good conscience even to beginners. But I do not recommend the PureUV bulbs to date until I figured out a way to use them at the same heigth with the main light source without damaging the plants. To use them 30" above the canopy is simply not efficient enough. You could supplement double ended HPS bulbs with them but LED lights would hung in front of them and you would get areas with no UVB.

 

[SoMe_EfFin_MasS_HoLe]

The most easiest way to add these wavelength to your grow area are good reptile bulbs. The good ones have up to 14% and 30 UVA and they do not harm the plants. I can not say how these Flowerpower bulbs work but I can say, these Agromax PureUV are for sure too strong for beginners.
I've used reptile bulbs with good success and wanted to try these Agromax beasts but they are too strong to use them with less than 24" distance. Mine are currently 24-28" above the canopy(a 2ft bulb per 2x 2' area) and I have already wilting leaves with 3h per day. Its reduced to 1h per day now but I need to wait a few days to see if the wilting stops or not.

Thats especially strange cuz the intensity level is lower compared with the reptile bulbs which I've used with only 8-10" distance.

Could a light mover help to reduce the stress? Probably yes! Would be almost the same as when you use only short UVB pulses of 5 minutes but 12 times the day.
I'm just trying to figure out how to make good use of it. Maybe I have to go the pulsed way but for T5's its the worst case scenario. Such bulbs need a few minutes to warm up and stabilized their UV output and then they're already switched off?
That certainly accelerates aging..

Reptile bulbs (with 10-14%) or the Agromax 10k finisher I can recommend with good conscience even to beginners. But I do not recommend the PureUV bulbs to date until I figured out a way to use them at the same heigth with the main light source without damaging the plants. To use them 30" above the canopy is simply not efficient enough. You could supplement double ended HPS bulbs with them but LED lights would hung in front of them and you would get areas with no UVB.

I know this is op' thread but thanks for the info Blame! Have not had a chance to speak with you in a bit but hope all is well Brother.

 

[rkymtnman]

Mine are currently 24-28" above the canopy(a 2ft bulb per 2x 2' area) and I have already wilting leaves with 3h per day. Its reduced to 1h per day now but I need to wait a few days to see if the wilting stops or not.

I had pretty good luck running them for 15 mins on but only 4 times a day. my thinking was trying to mimic sun where the highest uv is during 10 am to 2 pm (when you should be at the beach bar drinking instead of laying on the beach burning)

but you are correct, these bulbs will melt leaves if not careful.

 

[Randomblame]

I had pretty good luck running them for 15 mins on but only 4 times a day. my thinking was trying to mimic sun where the highest uv is during 10 am to 2 pm (when you should be at the beach bar drinking instead of laying on the beach burning)

but you are correct, these bulbs will melt leaves if not careful.

Yeah, its a strange beast. I've used them for 3h(2x 1,5) at 32-36"... no problems! I've already hardened them up in veg beginning with 2x 5 mins, then 10, 20, 40, 60 and with the switch to 12/12h they run for 2x 90mins with no issues. Whole hardening process takes 2 weeks... Distance still 28-32".
These wilting problems start with 24-28" and it occured in just 2 days.
I've set 3x 20mins for now and hope they'll recover.. At which distance have you used them? +24" is a bit too much for my taste and I would rather use them between 16 and 20".. Maybe I'll find a way to underdrive them. The Solacure 4ft bulbs can be used with 20, 32 and 40w. So maybe there is a way to dimm T5 bulbs too.

 

[PrometheanLeaf]

Not dimming t5, but the driver in the ballast.

 

[rkymtnman]

At which distance have you used them?

i was somewhere in the 20 to 24" range.

 

[mr. childs]

what ive found out over the years is that the pure uv 2ft bulb even causes oxidation on the heatsinks for the cobs. the silicone sealing around the cobs doesnt look to be affected as much. i have gone as close as 1ft away during 12/12.

 

[Randomblame]

i was somewhere in the 20 to 24" range.

Thanks, mate!
I'm currently at 24" and have reduced to 3x 20mins cuz the Sonoffs are limited to 8 switches per day, even the dual channel Sonoffs. One side has the far-red diodes, the other channel controls the UVB balast. I will change that and use a single Sonoff with the UVB to extend it to 4x15mins.
The other channel gets a few Osram Square 660's and a 20w driver.

I found a 0-10v dimmable balast yesterday which allows it to dimm the light from 1-100% and have ordered one to replace the exsisting one(~30 bucks). I'll also get a single bulb ballast for my other little area. Found them on e3ay...

Philips HF-Regulator 124.TL5/220/240 is for one bulb and 224.TL5 for two bulbs. For dimming you can use the rapidled 0-10v dimmer or Osrams Pico SL20. But this dimmer has an additional lux sensor to automaticly set brightness according to the daylight level.

 

[Randomblame]

what ive found out over the years is that the pure uv 2ft bulb even causes oxidation on the heatsinks for the cobs. the silicone sealing around the cobs doesnt look to be affected as much. i have gone as close as 1ft away during 12/12.

1ft with the Agromax, really???
Did you used them pulsed with 5 minute per hour pulses? At only 1ft. a pureUV bulb would burn them girls their asses off? How did you managed it without harming the plants?

 

[Randomblame]

Here are a few shots of the scrogged Bubba'sGift(Humboldt seeds) getting ~120w LED and 24w UVB from an Arcadia bulb. Today is day 42 and she already starts to fade out. In the end the whole plant gets purple, black and yellow leaves and purple buds. Some of the leaves gets almost black and the UV bulb increase it even more.



Highest tops are 8" away from the bulb which should give me at least 150μW/cm². It's only a small 28x 14,5" area and its probably much more UVB if I look at the Arcadia test results.


The lowest reading they get with the widest reflector and 8"/20cm was ~250μW/cm² measured in the center. So with my ~150μW/cm² assumption and 5h per day she should have ~27kJ/m².
It's pretty easy to figure out the daily UVB dose by multiplying the measured μW/cm² by 0,036 to get kJ/m²/h. 150μW/cm² means a dose of 5,4kJ/m² every hour.

 

[mr. childs]

1ft with the Agromax, really???
Did you used them pulsed with 5 minute per hour pulses? At only 1ft. a pureUV bulb would burn them girls their asses off? How did you managed it without harming the plants?

yup, turned the plants into fried veggies. i will look on my old phone to find the pics soon

 

[mr. childs]

pics from 2017. the bulb in there when i took these pics was the standard 6500k bulb from htg. i have to look on another phone for some older pics. i think that was a run of black triangle.

 

[Merlin1147]

Call Dennis at Solacure. He has some 2’ bulbs that were miss printed “Solarcure”. He’s a great guy, very knowledgeable and gave me a super price break on them. They are T-12s. I bought his fixtures. They run on the same ballast as the 4’ bulbs as it is nearly impossible to get the ballasts anymore for the 2’ T-12s. They are hung but I haven’t run them yet.

 

[Merlin1147]

Ps they have a build in reflector inside the bulb.

 

[bearded.beaver]

From personal experience of adding a reptile CFL uvb I burned the hell out of aloe plants. I had the bulb in a clip on desk lamp and I thought it would be good to put over some baby aloe I had just replanted. No good burned them.
So just be careful. I do think supplementing with added uv can help with tricrome production. But as for hard facts I got none other then "well the sun has it"