UVB grow light

[Wian]

Apparently using a UVB light at the end of the flowering period for a couple hours per day will increase THC and other cannabinoids..

So I am looking for a good UVB light, but can not really find any.

Any recommendations/experience/opinions?

Thanks!
Wian

 

[DCLXVI]

Myself and @Mañ'O'Green both use T5 UV lights. I have the agromax pure UV and I forget which ones exactly ManO has. I got mine from htgsupply as it was nicely priced for the housing and bulb. They have a couple to pick from in 2' and 4' lengths.

Solacure also make some nice UV options. If I upgrade my new 4x4 with UV I will probably run the Solacure tubes.

I have not seen great LED options yet. Most are the fluorescent tube style bulbs but they affordably put out UV A&B.

Interesting articles: Do read skeptically as they are from the manufacturer

AgroMax Pure UV T5 Bulb – AgroMax

New Grow Hack Increases THC Levels By 28% – AgroMax

 

[JaxsoNL5]

I’m only on my second grow so I don’t have experience to say it helps, but I also run the AgroMax PureUV (75% UVB, 25% UVA). My opinion though is growers through so much into lighting in an attempt to recreate the sun indoors, so adding UV should be a definite addition or you’re not really recreating the sun’s electromagnetic spectrum. The real question and discussion IMO is how much artificial UV to dose the plants with? The sun doesn’t just stream a constant amount of UV radiation, or any specific wavelengths for that matter, so blasting a plant indoors with a focused relatively high intensity UV bulb should be an obvious no. But controlled doses to initiate the UVR stress response may likely have benefits, plants have enough repair pathways to deal with damage so it may speak to something that cannabis and some plants have robust UVR stress response pathways. I have a T5HO fixture dedicated for the UV bulb and personally start with 5 min UV at “midday” during mid-late veg, doubling it every few days to acclimate. By the time she’s in flower I’m going 2 hrs constant at midday and max light intensity (I dim around the midday showering of light). Late flower I pulse randomly 5-10 minutes a couple hours after lights on and before lights off (plus the 2 hrs at midday) to add additional UV stress. Again just my opi FWIW

 

[Mañ'O'Green]

I use both the UVA plus and the Pure UV. The UVA Plus runs from real flowering to harvest 18/6. The Pure UV just a couple of hours a day the last two to three weeks.

Bruce Bugbee says it does not work but my personal experience says it does!

 

[N/A-Greengo]

California Lightworks has fluorescent UVB fixtures.

 

[Wian]

Thanks for the replies guys!

Looks like the brands you guys mentioned are not available to me here in Europe. If I find anything that is not for reptiles I think I shall be happy!

 

[DCLXVI]

Check with Migro out of Scotland.

https://migrolight.com/collections/all/products/migro-uvb-310-fixture-and-fluorescent-tube

 

[CannabisMingus]

I was running a Solarcure Flower Power until I drilled down on some more recent research and discontinued it due to concerns over terpene loss and efficacy. While there are some older studies showing that you need wavelengths down to 285nm to activate the UVR8 protein which is (partially?) responsible for increased THC production some of the more recent studies call into question that conclusion. I identify a couple here. IIRC, all the studies I looked at found enhanced terpene loss with UVB and mixed reviews on THC production - but I was probably baked when I read them. IMHO, YMMV, etc.

 

[DCLXVI]

I was running a Solarcure Flower Power until I drilled down on some more recent research and discontinued it due to concerns over terpene loss and efficacy. While there are some older studies showing that you need wavelengths down to 285nm to activate the UVR8 protein which is (partially?) responsible for increased THC production some of the more recent studies call into question that conclusion. I identify a couple here. IIRC, all the studies I looked at found enhanced terpene loss with UVB and mixed reviews on THC production - but I was probably baked when I read them. IMHO, YMMV, etc.

I'm glad you posted this! Very good to have a different angle and new studies to look into. I'm only into the UV toys about $65 and quite interested in the new data before I spend a decent amount on new tubes and lights. I had also seen the older data on wavelength and was one of the reasons I ended up going with the T5 fluorescent tube over the LED options. Only the tubes were putting out both UV-A and UV-B. From what I could tell the data suggested that the shorter "B" ƛ was needed, with "A", and no LED source was able to do that yet except in very narrow ranges.

 

[Wian]

Check with Migro out of Scotland.

https://migrolight.com/collections/all/products/migro-uvb-310-fixture-and-fluorescent-tube

Thanks! Totally oberlooked this!

I was running a Solarcure Flower Power until I drilled down on some more recent research and discontinued it due to concerns over terpene loss and efficacy. While there are some older studies showing that you need wavelengths down to 285nm to activate the UVR8 protein which is (partially?) responsible for increased THC production some of the more recent studies call into question that conclusion. I identify a couple here. IIRC, all the studies I looked at found enhanced terpene loss with UVB and mixed reviews on THC production - but I was probably baked when I read them. IMHO, YMMV, etc.

Thanks fot this. Now you have made me doubt

I will need to do more reading now!