I expect some people do buy High Pressure Sodium lights at Home Depot and
use them for growing plants indoors. They are brighter than High Density
sodium lights for the same amount of electricity. The design of the
reflector around the light is not particularly important, as long as it is
safe, but there are differences in results between the various styles.
There are alternative sources for HDS lamps besides Home Depot and online
sellers. In my city several hydroponic shops offer a selection of lamps
together with ADVICE.

"MC" wrote in message
om...
I have read some people by the HPS at Home Depot and wire it for
growing plants indoors. I am planning on doing this given the
difference in price ($80) vs online sellers ($150). My question is
does the housing make much of a difference in how the light is
distributed? From the looks of it, the real HPS grow lights seem to
direct more light in a concentrated fashion while the HD lights are
for lighting a parking lot or something.