very green leaves
 

Anybody grow their orchids under artificial lights? I live in southern Nevada where it would take a lot to run a green house. Cooling in summer, heating in winter. I just started growing my Cattleyas, Moth, and Pansey under LED red and blue lights bought from E-Bay. I know what other people use these lights for but I thought I would try this for Orchids. My only concern is, they have been under these lights for about three months now. I never have seen the orchid leaves so deep green. I read somewhere orchid leaves when they get enough light they could be a green, yellow color. Any ideas??

Do not think, for a moment, that what you have read or heard applies to ALL orchids. The three you mention all need entirely different conditions from each other, and will appear different when grown well.

That said, generally speaking, dark green leaves can be an indication of insufficient light levels. How far are the plants from the lamps, and what wattage is it?

In terms of preferred light levels catts need the most, the miltoniopsis and phal are fairly close, but I'd say the milt needs a bit more than the phal.

I think its more a light apple green colour.

how long are the lights on for? you could try increasing the duration they're on

maybe some body with more experience with the led lights can chip in :)

edit: somebody has - what he said :)

They are on for 14 hours per day and are about 15 inches above the plants. The Catts. are directly under the light, the other two are around the perimeter where the light is less intense. The light is 300watt.

Something is wrong. 300W, 15 inches above the plants? Are you sure?
Turn off the lights may be is optical illusion; 300W LED is equivalent to 500W HPS.

That's what the light is rated at. light is equivalent to 300w uses about 100w

LED spectrum is probably useless for photosynthesis. If you use 100W LED (450-470 and 620-660)nm leaves of cattleya turn red.

Plants need photons of the correct wave length for chlorophyll to use (color) and they need a sufficient number of the photons for good growth (brightness, guesstimated by Watts, since photon output is sort of correlated to electricity input.) All plants use similar wave length photons but different plants need different amounts of photons. Your catts need a lot more light than you pansies/Miltoniopsis. You can almost certainly grow moths/Phalaenopsis in a north or east window, and Catts if you have a sunny window. The Miltoniopsis generally need cool temperatures. They will not be happy with the temperature unless the Catts and Phals (which like warmer temperatures) are unhappy.

LED lights are pretty new to orchid hobbyists and things are still being figured out. Plus a lot of fixture assemblers who wholesale to retailers source LED lights from varying sources so the specs may vary from what you might expect. If you search the forum for the terms CFL and LED you will find a lot of information to wade through and get confused. A member named naoki has contributed a lot of information on LEDs.