[DierWolf]

If UV light was harmful to plants every plant outside would be dead by now because of the amount of UV the sun puts out.

There is UVA, UVB and UVC, sun puts out all three and the UVB and UVC are the only harmful ones (causes skin cancer in humans) UVA is not harmful. UV provides Vitamin D3, which all plants and Reptiles require for healthy growth.

In fact your using UV as well, its the reason your using Flourescent bulb / MH / HPS instead of Incandecent bulbs, as incandecent puts out so little UV it does nothing for the plant.

Nasa cant stop a piece of foam from flying off, i would not use them as a reference if i were you.