I tried a metal halide grow light for a few months. I thought I could
overwinter my container plants and save some $$. My light bill went
up $40/month, though, so it wasn't much of a bargain. Besides, it
made the growing room very hot. I'll try regular fluorescent bulbs
this winter.

-- pelirojaroja

"Joseph Meehan" wrote in message ...
Wide spectrum lamps are good and they are the easiest solution, but you
will never see them in a commercial application where mercury vapor is
favored due to the overall cost savings. Over the total life of the fixture
the cost of lamps, fixtures and power strongly favors the mercury vapor.
Just ask any pot grower.

--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math


"zxcvbob" wrote in message
...
Joseph Meehan wrote:
Generally you can use just about any fluorescent light.

You plants will appreciate it if you add some incandescent lights as
well to make up for the missing colors of most fluorescent lights. This
is
less important or not needed at all if you use the more expensive garden
or
plant type lights.

Using cheap fluorescent fixtures is a waste, the better (electronic
ballast type) last longer, don't hum and are more efficient.

If you are going big time, consider mercury vapor types. They are
even
more efficient and the point about adding some incandescent light still
applies.

Different plants need different mixes of lights so experiment. Have
fun. It is more art than science.



Mercury vapor? They are expensive, and only about twice as efficient as
incandescent lamps, and their spectrum is about as bad as high pressure
sodium lamps. You kind of get the worst of both worlds.

Triphosphor fluorescents approach 100 lumens per watt, and they maintain
their luminence much better than most discharge lamps.

If you think broad spectrum is important (plants don't seem to think it's
important), use GE "Sunshine" fluorescent lamps (available at Wal-Mart,
IIRC they come in an orange package), or Philips TL90's.

Best regards,
Bob