Light is expensive. Lumen for lumen, the fluorescents will be more
expensive. However in you specific case they may prove to be less expensive
overall for a number of reasons. Either should be less expensive than
incandescent.
--
Joseph E. Meehan
26 + 6 = 1 It's Irish Math
"-- pelirojaroja" wrote in message
om...
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