You might want to put some kind of diffuser on it to avoid bright/dim spots, the brightness loss isn't too much of an issue as you can just let it stay under it longer. We can't see the UV but we can see the portion of it that extends into the upper Violet range, the primary frequency it puts out is invisible to the human eye. If you put a UV light next to something that fluoresces under UV light you'll notice how much brighter it is than the apparent UV source, and that's a secondary reaction.
Cobra, I'm not sure why you think UV is so limited, it's nothing more than a colour of light that's just outside our visual range, birds have been shown to be sensitive to UV light, and can see interference patterns in the day sky cause by UV light diffraction patterns as part of their geolocation systems. That's UVA though, you may be thinking UVB or farther up the UV spectrum, down actually as it goes clear on down to 10nm's. UVA is only 400-320nm