There's three things about florescent tubes:

They lose a lot of their ability to put out light in the first month or so.
So a 1 month old bulb of the same type will look dimmer than a new bulb.
They also slowly drop in the amount of light they put out. Florescent tubes
should be replaced every year. Most aquarium people who grow plants replace
them after 6 months because they just lose too many lumens. Compact PC
florescent lights (don't confuse with small florescent lights) don't have
this problem and last a very long time. They are expensive though.

The sun puts out full spectrum which means all the shades of all colors.
Full spectrum florescent bulbs put out specific shades of blue, yellow, red,
and green. So whereas the sun would put out 100 shades of green a florescent
bulb will only put out 3 shades of green. Plant lights put out mostly blue
and red and normal office lights put old mostly green and yellow (what
humans see best)

There's also a "temperature" of the bulb. Don't confuse this with heat, it
has to do with how we perceive the bulbs color. This appears to us as either
blue or red or a mixture (i.e. kinda violet). When you see something like
"5000k" it's the temperature. A lower number means it'll be more red. A
higher number means it'll be more blue. "Cool Whites" are higher temperature
and "warm whites" are in the lower temperature. Most full spectrums are
5000k.



"D K" wrote in message
.net...
To continue on a thread that doesn't seem to exist any more.... I went
Home
Depot, bought some full spectrum florescent light bulbs (they have 4' and
8'
in 2 brands) @ $8.99 each and installed them in our kitchen light which
takes florescent tubes. Since we just did it I don't know how it is going
to work. I gotta tell ya though that the lighting is really strange. It
actually looks blue... sky blue. The other lights in the house look
yellow-red in comparison... It is odd because it looks really much
brighter
but the watts are the same as what we had.

DK