Lighting My Orchid Cave

[Ray]

I could be wrong about this, but I think that in an enclosed chamber, MH or HPS lights may generate way too much heat. I think high-output T5 fluorescents would be the way to go.

For a 7' x 5' growing area, you could put up as many as three 4' x 8 tube fixtures.

Don't forget that no matter what light source you use, the inverse-square intensity drop-off still applies, so you'll have some differences in light levels over that 6-foot height.