UV Suppliment Lighting

SMT69

Well-Known Member
I'm sold on the reptile bulbs for small tents, these are working nicely (for now, i really want LEDs). Ive got the 24w ones so they seem they've got the power. They also emit a bit of blue visible light that makes it easy to see the coverage and adjust distance.

Currently now backed off slightly, running the UV at 4 doses of 30 minutes and monitoring if they handle that everyday

One thing I noticed it made them stink up quite a bit
...now if i can get through this without cookin' um...

 
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carlo987

Active Member
It has a 6"so area. It's not practical at all. and Fucking huge. Pretty sure that things at least 4' talk.
Looks expensive as well.
Clearly, it would not be used for a closet or garage type grow. Just for research in a commercial facility... and it would need like I said a minimum 2x2 ft beam. That thing could be anywhere from $20k-200k. Am not even going to ask for a price, but having a thing that allows absolute control over UVA/B quantities, full spectrum, intensity going up to the intensity of 1.5 suns would be a dream. Apparently they use Xenon lights.
 

SMT69

Well-Known Member
12" seems to be the right height for even UV spread in my setup/ ive had to dial it back to 30minutes @ 4 times (2 hours total currently). new growth is looking great, one hour x4 was too much...seeing no hot spots either which i was worried about.

you can see the lower leaves where i gave um too much days ago, and the new growth is just about right with half the doseage. i'll flip these slurricane ix in a few days




Theres 5 different seed mums there, same strain, and definitely some take the uv better than others, like others have been saying

I'm aiming for max potency, really. my concern now , is pushing them with too much UV and this is probably a sensitive hybrid strain, so I wonder if you could push them in to throwing balls with too much.
 
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ChiefRunningPhist

Well-Known Member
Lol well I do love star trek references :bigjoint:

A few things I wanted to hit on. Whether you're 3000m in elevation or 2m in elevation a 10 UV index will be pretty much the same regardless.
View attachment 4343453
The UV index is a measuremt of UVB in 3 WV spots (295nm, 305nm & 325nm) with each WV given different weight on the final calculation than the other. This is due to the the absorption rate of UV light on most molecules.
View attachment 4343454 View attachment 4343455
The smaller the WV the more easily it is absorbed by water, DNA, ect, so the smaller the WV the greater the weight on calculated UV index. Australia is not very high elevation but has UV indexes of 14+! So UV index may correlate sometimes with elevation but it is actually only dependent on real life UVB radiation measurements regardless of elevation.

I'd have to ask for some data showing that 1000m elevation outdoors isn't enough UVB to notice a difference. They grow weed here in California pretty well and that's about sea level. Even vulcans will sunburn at the beach lol

μ (micro) = 1×10^(-6)
m (milli) = 1×10^(-3)

100μw/cm2 = 1w/m2

450μw/cm2 = 4.5w/m2 which is more than 8× more UVB radiation than a 10.6 UV index. I'm not sure what UV index that would correspond too.

500μw/m2 = 0.0005w/m2 and isn't very much UVB.

It'd be nice to have a PC UV chip, but 290ish nm chips are dismal effeciency and you'd have to use that as your pump because you can't upgrade photons. I think the best LED UV will be more than 2 WV. I'm trying to include as many as I can. So far I've found 305nm, 310nm, 320nm, 340nm, 365nm, 385nm, and 395nm.

I agree about 285nm. I want to try, but like you said I think there's benefit to a wider SPD. So if I'm going wide I'll have to include the other WVs anyways, so personally I'm going to try to reach into 290ish with my 305nm leg, but that's about as far as I'm going for targeting 285nm this time around. If I wasn't including other WVs then I think 1 or 2 chips of 285nm would achieve UVR8 activation like you enlightened me to in some of your earlier knowledge dumps :)

https://en.m.wikipedia.org/wiki/Ultraviolet_index

EDIT:
They weight the area under the UV portion of the SPD towards 295 at 100% and 325nm at 0.3% I think they go all the way till 400nm at true 0% (exponential scale). Then this weighted quantity of UV radiation is divided by 25mw/m2 to determine UV index.

So @Randomblame I believe my total radiation comparison in a 10.6 UV index day at 0.55w/m2 is off because I don't know the actual quantity (area under curve) from 290nm - 400nm, I only know 3 WV intensities. Looks like you'll have to downgrade my Vulcan status aha

I guess the take away for me is that UV index is a decent gauge imo when calculating a doseage range of UVB radiation, but that UV index says little about the quantity of UVA present.
*correction*
This is mostly correct, but it's not just 3 WV spots, those were only the 3 WV intensities given in the link I referenced.

They actually measure on a continuous scale, not only 3 spots, but every spot. Its like how lumens are weighted to the WVs your eyes are most responsive too, UVI is weighted to the WVs your skin is most responsive too.

A 5000k light will have more lumens than a 3000k light even though they draw the same wattage, just like a weak UVA reptile bulb and a UVB Agromax will have different UVIs even though they draw the same wattage. 1 bulb has an SPD that human skin responds to more so than the other, even though they might put out the same radiometric intensity or draw the same wattage.
 
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carlo987

Active Member
I'm just worried about the 12" distance.... I just ordered new LED lights from China and I do not think, that I will be able to run them at 12"
 

carlo987

Active Member
Did you have contact with them? I'm thinking of getting some reptile lights now for somewhere between $2.5 - 3.5/bulb. I've been looking at these. Am I getting my inverse square law wrong? Looking at the 30W f.e. at a distance of 4" they give off 140 uW/cm2 and at triple the distance 12" 59 uW/cm2? Shouldn't that be 140 x 1/9???
 

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Airwalker16

Well-Known Member
Well it looks like the UV game has finally made it's way to LEDs. @welight at cutter seems to have all kinds of options now on their website for all different wavelengths. Im starting to believe bulky 2'/4' fluro bulbs and t5 ballasts aren't going to be needed anymore. kinda glad I waited. I think I'll be purchasing a few of the 285mm single stars. Maybe 12-16 per 4X4?

https://www.cutter.com.au/product/cutter-zge-285-dxp-custom/

Also Mark, I can't find anything on your site that's showing single star pad UVs. It's a very recent post to instagram where you showed pics of them.

Those are what I'm more interested in for spread.
 
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Warpedpassage

Well-Known Member
Well it looks like the UV game has finally made it's way to LEDs. @welight at cutter seems to have all kinds of options now on their website for all different wavelengths. Im starting to believe bulky 2'/4' fluro bulbs and t5 ballasts aren't going to be needed anymore. kinda glad I waited. I think I'll be purchasing a few of the 285mm single stars. Maybe 12-16 per 4X4?

https://www.cutter.com.au/product/cutter-zge-285-dxp-custom/

Also Mark, I can't find anything on your site that's showing single star pad UVs. It's a very recent post to instagram where you showed pics of them.

Those are what I'm more interested in for spread.
https://www.cutter.com.au/product-category/diy-led-kits/horticulture-lighting/grow-led-colors/round-printed-circuit-boards/

I think these may be what u are looking for.
 

ChiefRunningPhist

Well-Known Member
Well it looks like the UV game has finally made it's way to LEDs. @welight at cutter seems to have all kinds of options now on their website for all different wavelengths. Im starting to believe bulky 2'/4' fluro bulbs and t5 ballasts aren't going to be needed anymore. kinda glad I waited. I think I'll be purchasing a few of the 285mm single stars. Maybe 12-16 per 4X4?

https://www.cutter.com.au/product/cutter-zge-285-dxp-custom/

Also Mark, I can't find anything on your site that's showing single star pad UVs. It's a very recent post to instagram where you showed pics of them.

Those are what I'm more interested in for spread.
This is how I'm thinking about UVB..

I think 285nm will absorb at least ~3× better than 295nm+. So if using 285nm, you'd take the mW/ft and multiply by 1.29 to get an equivalent UVI at system level. Its just a ball park to get an idea, the tent walls and the light fixture will absorb some of the emissions, ect..

Example:
2'×4' tent with (6) 12mW output 285nm chips.

2' × 4' = 8ft2
6 × 12mW = 72mW

72mW / 8ft2 = 9mW/ft2

9mW/ft2 × 1.29
=
11.61 UVI for the tent.

I think a 5.0 UVI or less would be good for 12hrs duration. An 11.61 for 12hrs will most likely fry them.



Where does 1.29 come from??

285nm is 3× more absorbed than 295nm+. 295nm is the WV with the greatest erythmal weight. A UVI is calculated by dividing total EUV or erythmal UV doseage by 25mW/m2 to arrive at a final UV Index number. There are 10.76ft2 in 1m2.

(3× more absorbed) / [(25mW/m2) ÷ (10.76ft2/m2)]
=
1.291
 
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