Ray wrote:
Well Ted, I guess we can ignore light reflected from the plants, since it's
the wavelength they don't use. Then we have to speculate on the
reflectivity of the benches, floor, media, algae, moss, etc.

My guess is that it's insignificant compared to the incoming light.


Not contributing much to the discussion, but I did research some
interesting articles regarding light used, benefits of reflection for
increased light, even an old comparison of light bulbs.

http://64.233.161.104/search?q=cache...ed+light&hl=en

http://plasticulture.cas.psu.edu/DSuccess-mulch.htm

http://www.pubmedcentral.nih.gov/art...?artid=1062077

http://www.ccpo.odu.edu/SEES/veget/class/Chap_3/3_1.htm

http://www.thekrib.com/Lights/intensity.html

My sun room uses transluscent insulation under a clear roof, unshaded
windows. I've considered adding mirrors or foil against the back wall
to try to limit the shadowed places and balance the development of
plants. The plants are outside during the summer and get good light
coverage from most directions, but the blooms concentrate on the the
sunny side of the plant during the winter. In the southeast area of
the room the blooms on the cattleyas develop in all directions around
the plant.

Someone that uses supplemental light may try using bulbs with enhanced
spectrum designs or colored reflectors and filters to increase
different light bands in the spectrum.

Orchids take such a long time, even a single bloom season. There may
be more in the color of the floor and encouraged reflection of the
walls than most people have given credit in their pursuit of light.