Re: Lighting effiency

On Thu, 29 Jun 1995 03:39:03 -0400 you wrote:
>  fluorescent T12, GE Chroma 50, 1870 lumens, 40 watts,
>    46.75 lumens/watt (similar for a cool white)
>  fluorescent T12, GE rare earth, 2960 lumens, 40 watts,
>    74 lumens/watt (typical "aquarium" bulb)
>  fluorescent T8, GE rare earth, electronic ballast (!), 2650 lumens, 27 watts,
>    98 lumens/watt  (part is T8 and part is electronic ballast)
>  MH, E37 VBU, 31000 lumens, 400 watts,
>    78 lumens/watt

With the figures above, why would anyone go MH? 
They are expensive, dangerous, and black body at
best.  Why not go for phosphors tuned to plant
needs?  I am not saying such a tube exists, but I
am saying it is the best choice.  Sylvania MUST
have data on GroLux, it's been out for 40 years.
Dave Gomberg, Experimenta      San Francisco CA      gomberg at wcf_com