Al asked:

What is PAR and why is it important? I know I am usually the first one
to say "look it up" :-) But it might be nice to get some of this in the
archive, if it isn't already there. I am lazy too.

"Photosynthetically active radiation."

PAR is that portion of the electromagnetic spectrum that plants
can use to make energy. You can spend a million bucks simulating pure
sunlight- the plants won't care, since they don't use it all. See for
example:

http://ww2.mcgill.ca/biology/undergr...t07/absorb.gif

Nice peaks in the red and the blue, and a whole lotta nothin' in
the middle. Plants also use "helper" molecules to capture photons outside
of these regions; their contribution is relatively small.

The e-mail address in the header doesn't work. Spam trap.

-AJHicks
Chandler, AZ