UV supplemented lighting

Seems they where all the rage a few years ago. Then they kind of fell to the way side. Now I see they're back as supplemented additions to LED, CMH and other fixtures.. Also a big advertising feature for MH, CMH, and HPS. Solistek even came out with the 10,000K "finisher".

so what is the word on these? Do we have proof?

yay? nay?

Granted as sun light passes through the Earth's atmosphere some Ultra Violet B radiation filtered. Yes. It is worth it. My current grow has thicker leaves than any other grow, I have done without UV supplementation. UV is part of the sun's spectral output everyday.

If you are going to supplement UV radiation it is better to get the highest output you can afford. I am currently using a UV bulb designed for the atmosphere of a desert.