UV Supplementation

[Baphomatt]

Good morning! How's everyone on the Group W bench?

There seems to be some pretty strong evidence that UV light supplementation can significantly increase potency. Some proponents say to supplement during the last few weeks of flowering and some say use it throughout the grow.

Do any of you have any experience in this area? If so, what type of setup and schedule do you use? Any other relevant advice is, as always, more than welcome.

Have a great day & good growing!

[DrPhoton]

UV supplimentation should be looked at carefully. Fluorescents that specialize in UV output are the only ideal technology for UV emission. Other technologies such as LED's are not efficient enough to provide any beneficial return. All LED products that provide UV features are just taking your money.

The application of UV must be done properly to prevent negative effects such as reduced photosynthetic rate in leaves. So it is often recommended to only use UV at the last week or two.

Have a look at my article on comparing lights, i believe i mention UV there.

[Sheesh]

My California Light Works SS440 LED has two separate fluorescent UV lights. I believe they are UVb and there is a separate switch to turn them on. The recommendation from the vendor is to use them in the last 2-3 weeks of flower. I have no way of knowing if adding this lighting late in flower helps me or not since I've always used the UV. My 440 flowers a 3x3 footprint really well with 320 true watts in bloom mode (350w with bloom+UV). Maybe the UV does help since that is not a ton of lighting but I pull 10 oz from 3 plants. It's about 35 watts/sq' which is in range but can be higher. I'd look into the SS550 but my 440 still works great and they are not cheap, I think about $800.

As far as adding UV to existing lighting I'd say google it and see what is out there and try them late in flower. I doubt they are very expensive and wouldn't add too much heat or power load.

[kingfish]

I read once the glass shield on the hood of your light reduces UV. So I removed it. I have yet to see if it makes any difference.

[DrPhoton]

Its insignificant.

[Baphomatt]

DrPhoton - thank you! There's a wealth of information there. I've read what I could already (I'm at work) but will be revisiting it when I can really digest it. I started researching light to help me select new LEDs and that's taken me off on several tangents. It's absolutely fascinating! I may be hitting you up with a follow-up question or twenty.

Thank you all for your insight, I f'n love this place!

[DrPhoton]

No problem, any questions ask away.