THC, CBD, Terpene test results – UVA vs UVB vs none

Hey mate, @PSUAGRO. asked the same question above. Seoul Semi told @Grow Lights Australia 50K, but he reckoned at least 30K going by Nichia specs.

good job

do you think 6% uvb is much of a uvb test?

I agree it would be cool to see the results with only uv-b and maybe a higher %?


I currently am running qb 288 Rspecs.. Wondering what of these I may want to add into my 5x5? the far red I shouldnt need because the R spec boards right?

OLD MOTHER SATIVA said:

good job

do you think 6% uvb is much of a uvb test?

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Sunlight has about 5% on average – though the level of UV varies depending on all the usual factors – so it's probably about right. You could use more, but would you run it for the full 12-hour cycle? And if not, would there be a big difference between 12% UV 4-6 hours a day and 5% for the entire 12 hours?

OLD MOTHER SATIVA said:

good job

do you think 6% uvb is much of a uvb test?

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Yes mate, weed is def more potent / sticky.
I'm lazy and Random thought it would be easier for me than extra timers and my penchant for pushing the envelope, plus everything runs at same height.
I also use my old 6%ers for the last week or so of veg.
FC

Prawn Connery said:

Sunlight has about 5% on average – though the level of UV varies depending on all the usual factors – so it's probably about right. You could use more, but would you run it for the full 12-hour cycle? And if not, would there be a big difference between 12% UV 4-6 hours a day and 5% for the entire 12 hours?

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good reply..

test had lights with no uv with uv..my post was about ... a test using white leds with just uvb and no uva

..so you could see what effect it has on its own

OLD MOTHER SATIVA said:

good reply..

test had lights with no uv with uv..my post was about ... a test using white leds with just uvb and no uva

..so you could see what effect it has on its own

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Well two of the tents had UVB + UVA. One had UVA and near-UV with no UVB. And the control tent had no UVB, UVA or near-UV.

So there were two tents with no UVB, and of those, one had a small amount of UVA and near-UV, and the other had none. That's three different spectra to compare.

Looking at the results, UVB did not appear to help the two tents that had it. Because their THC/CBD and terpene levels were very similar to the High Light tent. So all that remains is, would UVB on its own produce a better result? And if it did, would that suggest that UVA and/or near-UV interfere with UVB stress-induced cannabinoid production?

Based on this test – and it is only one test, even though there was a good range of samples using the same genetics, nutrient and propagation techniques – I would have to say the addition of UVB around 315nm (where it peaks) offered little advantage over near-UV.

A 20% increase in THC and CBD, and a 25+% increase in terpenes is also a good result. This test backs up the other scientific test link I posted earlier, and there were two separate tests in that experiment. So that's 3 out of 3 so far that confirm higher cannabinoid and terpene levels with added near-UV (400-420nm) without the aid of UVB. And, anecdotally, nearly all growers using High Light boards with UVA/near-UV have reported the same increase in smell, oiliness and perceived potency.

That's my take on all of this. Of course, you could say I have a vested interest – which I don't deny.

Nizza said:

I currently am running qb 288 Rspecs.. Wondering what of these I may want to add into my 5x5? the far red I shouldnt need because the R spec boards right?

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My money would be on the UVA, but I'd want to get some near-UV (around 420nm) in there too.

This thread needs some pics............else it ain't realio?

This is the High Light tent a couple of weeks or so before harvest.

Prawn Connery said:

My money would be on the UVA, but I'd want to get some near-UV (around 420nm) in there too.

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So would one of these https://horticulturelightinggroup.com/collections/all/products/hlg-30-uva-supplement be enough to go with my two 320w rspecs? https://horticulturelightinggroup.com/collections/kits/products/320w-xl-qb-v2-led-kit

and what do you recommend for figuring out distances from canopy with these?
If buying just one of the UV-A lamps would be enough that is great they are expensive! I would love to get more flavor and potency and if 150$ will get me it I would like it alot, just not sure the best route to go

also do you only use the uv-a during flowering?

those high lights are cool but I can't invest any more money into lights except maybe small supplementals I have no space where I am now.

Lead with those prawn............that is a solid sales tool.

Grow Lights Australia said:

Hi PSUAGRO, we don't have L70 data on the Seoul Semiconductor STW9C2PB-S Sunlike LED however the Nichia NF2W757GT-F1-E Optisolis uses a similar "purple pump" (420nm) and it has an L70 of 30,000 hours according to the data sheet. The original Sunlike LED's had a 405nm pump but this was revised to 415nm prior to first High Light production. This changed the spectrum a little (as you can see below) but it increased the efficiency of the LED by around 10% and Seoul Semi also said it increased the life of the LED (but didn't give a lifetime estimate).

I have also asked Seoul Semi if they can provide the figure for you. L70 testing is done on 1.6mm FR4 with 0.07mm copper trace (2oz copper) and we use 2mm aluminium PCBs with 2oz copper, so the better thermal conductivity will help with LED life.

OK edit. Seoul Semi have just replied to me and stated



Here you can see subtle differences between the Test Board (405nm Sunlike) and the Production Board (415nm Sunlike) spectra.

Test Board
View attachment 4435991

Production Board
View attachment 4435990

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If the l70 data is accurate, that's generally good for the life of the board+beefy mcpcb..... Nice job

I would like to see hydro run with control, so watering habits don't skew. But that's me nitpicking...

Nizza said:

So would one of these https://horticulturelightinggroup.com/collections/all/products/hlg-30-uva-supplement be enough to go with my two 320w rspecs? https://horticulturelightinggroup.com/collections/kits/products/320w-xl-qb-v2-led-kit

and what do you recommend for figuring out distances from canopy with these?
If buying just one of the UV-A lamps would be enough that is great they are expensive! I would love to get more flavor and potency and if 150$ will get me it I would like it alot, just not sure the best route to go

also do you only use the uv-a during flowering?

those high lights are cool but I can't invest any more money into lights except maybe small supplementals I have no space where I am now.

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Well I'm guessing one of those should be about right for two 320W kits, as they appear to be designed to pair with the HLG-550 kits. I would hang it in-between the 320s at the same height.

I'd also run it only during flower, for two reasons: that's when you need it, and your LEDs will last longer. I'm not sure of the lifespan of those 365nm and 385nm LEDs, but they will likely be much lower than typcal white phosphor LEDs.

There are cheaper options, which include fluorescent reptile bulbs and actinic bulbs, which usually have a nice 400-420nm kick. You will need to replace bulbs every six months or so, but it's a cheap way to get into UV, and the bulbs are quite common and can usually be bought cheap at aquarium/pet stores or online.

Thanks alot prawn, I'll be getting one of the UVA fixtures for next run. I appreciate this info alot and thank you to all who are involved!

150$ for a possible 20% increase in taste and potency I think is a no-brainer when its only 30 watts more power! Gotta get some nice glasses now though for when the chamber is on!

PSUAGRO. said:

If the l70 data is accurate, that's generally good for the life of the board+beefy mcpcb..... Nice job

I would like to see hydro run with control, so watering habits don't skew. But that's me nitpicking...

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As we know, there are always variables and more tests are better. But at least these results appear to correspond with other scientific data that show the same. And I think you saw the grow in question, so you know it was done pretty well. He tried to match PPFD as close as he could, among other things.

Here's my 6% with Prawns HighRed boards, 5 weeks to go

"That's my take on all of this. Of course, you could say I have a vested interest – which I don't deny. "

> i didn't even think of it

so ok..no uvb only test was done..thanks

i have no vested interest either..

No mate, no UVB-only test. And the "vested interest" remark was purely for disclosure. I had a hand in designing and testing these boards, and I use them myself, so I think it's important that people know that when I talk about them. I have nothing to hide.

Why didnt you use Nichia 5000k. It has the same red colors and better blue spectrum. Maybe, than can produce near UV too.

Smoky Man said:

Why didnt you use Nichia 5000k. It has the same red colors and better blue spectrum. Maybe, than can produce near UV too.

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Hey, you sure seem to like those Nichia 5000K. I think I've answered the same question in the other thread, but can you tell us why you think Nichia 5000K make such good flowering lights? And are you talking about Nichia's Optisolis? Because if you are, then they are only a 100mA LED and about 45% efficient.