I don't have the footcandle output numbers but when I used the 40W fixtures
I would buy two shop lights each with two bulbs. I place these about 6-8
inches apart and kept them about 6-12 inches from the top of the plants. I
was using them in a basement as the only source of light for the plants. If
you are using them for supplimental light (like near a window) then you can
be further away from the tubes. I used the run of the mill cool and warm
light bulbs from Home Depot (1 of each in the two bulb shop light).

Remember that the bulbs lose their efficiency and need to be replaced at
least once a year.

Good growing,
Gene




"///Boochap///" wrote in message
...
hi, may i know how many footcandle do we expect from a 4x 40watt fixture?
and at what distance from the tubes?

"Gene Schurg" wrote in message
ink.net...
Joanna,

With the shorter light fixture you are fighting two different problems.
The
lower wattage means the plants would have to be closer to the tubes.
This
is an issue with 40W tubes and sometimes the leaves/flowers get fried.
With
30W bulbs I would think you have more problem with this type of damage.

The other issue is that the PEAK light for plants is toward the center
of
the tube. Plants near the end get less light than those placed toward
the
center. With a 3 feet long bulb you have less center to put the plants
that
need more light.

My guess is that this might work for the lowest light orchids.

Good Growing,
Gene



"J Fortuna" wrote in message
...
Ok, so we went looking for fluorescent light fixtures and bulbs today
at
Home Depot. I had envisioned buying a fixture with electronic ballast
and
with 2 40-watt cool and 2 40-watt warm light bulbs or maybe the GE
Sunlight or something like that.

Trouble is, we have space only for at most 36" long light fixtures --
the
space we have is 36" long by 18" wide. Almost all the light fixtures
are
48"
and the bulbs are sold only in 48". There was one fixture we saw that
was
36", but it was labeled only for 30-watt -- is that enough? I thought
at
least 40-watts was needed? And I am not even sure whether Home Depot
even
sells the light bulbs to fit this fixture.

We had been seeking fixtures rated for 40-watt bulbs, based on
previous
posts here. But we found all the 48" fixtures rated for 40-watt bulbs,
the
36" fixtures for 30-watt bulbs, and the 24" fixtures for 20 watts. Are
these
ratings really based on length? Is 30 watts over 36" sufficient
intensity?

Should I give up on the idea of getting fluorescent lights in my
limited
space? Any suggestions?

Currently I am growing my plants with a combination of northern
windows
and
Agrosun Dayspot grow bulbs, which come in 150-watts and 60-watts
sizes,
and
they are more spot lights. I am getting a light meter (already
ordered)
to
see how much light I am getting, but I suspect that while it is
sufficient
for Phals, it's probably not enough for any other orchids, and I would
like
to try growing others (if I had enough light I would like to try mini
cattleyas, dendrobiums, and those intergeneric Onc hybrids).

Appreciate any advice. Thanks,
Joanna