I recently purchased a quality $30 fluorescent light made by GE from
the hardware store that came in a box describing the product as
specifically for aquarium and garden use. Also in the lighting
section were other cheaper and larger fluorescent lights for
Are all fluorescent lights the same as far as gardening? In my
apartment I have plenty of indirect light but this will be the only
source of direct light for my plants. I kept the receipt and don't
know if I should take it back and do an exchange. I would appreciate
On 21 Aug 2003 13:40:05 -0700, peter firstname.lastname@example.org
(peter email@example.com) wrote:
The fixture and ballast (which "turns on" the bulbs) are
irrelevant--any will work as well as another, at least in teh short
The type of bulb is important. AFAIK, there are three basic types of
bulbs: cool white, warm (or soft) white, and wide-spectrum. Wide
spectrum is commonly used for plants because each of the others lacks
some of the spectrum (cool is more blue but less red, warm is the
other way round). You can put one of each of the cheaper bulbs in a
two-bulb fixture and compensate, but maybe not to the extent of
duplicating the output of two wide-spectrum bulbs.
That's all based on some research I did a long time ago--someone may
report a new type of bulb and/or fixture I don't know about.
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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
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.
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
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
Fluorescent IS mercury vapor, except that the envelope is coated with a
phosphorescent pigment. Mercury emission is rich in UV. That wavelength
roasts living tissue unless converted to visible spectrum. UV is wasted
on plants, anyway, since photosynthesis is most efficient with blue and
Metal halide uses Hg vapor and a mix of halogen gasses (iodine, sodium,
bromine, etc) to conduct the arc. Exact mix is formulated to approximate
natural, noon sunlight as closely as possible; televised night baseball
games were one of the first applications. Efficiency is excellent,
surpassed only by HPS, but more favorable for vegetative growth.
HPS stimulates floral development because its spectrum is close to low
angle, autumn sunlight. It was designed for cheap security lighting, where
color rendition doesn't matter. Home Depot annual flats are finished under
this type of bulb because unknowing customers are more likely to purchase
blooming rather than vegetative stage plants, which can better acclimate
themselves to their gardens.
Weak bands can be compensated for by adding a couple of the same tubes or
bulbs. Old-fashioned T12 fluorescents are cheap enough just to throw in
a couple more for insurance.
Use fluorescents if you're strapped for cash. Cool white tubes approximate
metal halide. Kitchen-bath tubes can be subbed for HPS.
peter firstname.lastname@example.org (peter email@example.com) wrote:
You'll get different opinions. You may not be able to see a difference
between full-spectrum and regular old bulbs. I have seen real
scientific-method trials prove it is better, but we all know
flourescent is not the same as sunlight. I used the more expensive
SUNLITE brand and I have no idea if it made a difference.
I bought a two-bulb unit, but found that I really needed wider
coverage. The plants towards the front and back didn't get much light.
For the spring I will have 4-bulb units instead.
As to cheap vs. expensive. Manufacturing sometimes makes things so
damn expendably cheap that you could buy 3 cheapo units or one
expensive. And I'm not sure the one would outlast three.
Energy efficient is important since you may have it on 12-16 hours a
day. Otherwise you will see big bills like another poster mentioned.
One item to remember. You'll want to put the unit on a timer, which
means you need one with a mechanical on/off switch. Some fixtures will
always be off when plugged in--which means the timer can turn it off
but never back on.
DiGiTAL ViNYL (no email)
Zone 6b/7, Westchester Co, NY, 1 mile off L.I.Sound
1st Year Gardener
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