Quote Originally Posted by raybark View Post
In order for a plant to grow and bloom, it must (among other things, of course) absorb a certain "volume" of photons. What that light source is appears to be less of a factor than the sheer number of photons they put out.

Your HID lamp puts out a ton of photons, but mostly in the blue end of the spectrum. Folks also successfully grow under HPS, which is mostly in the red end. When I started, I used 50/50 wattage-wise incandescent bulbs (red) and cold white fluorescent shop lights (blue). In LEDs, you can go with red and blue, or white, and as I have been saying over and over, as long as the photon flux and the duration of exposure are sufficient, you're golden.
Hid with a regular halide bulb would not flower many orchids. I stumbled upon agrosun bulbs which are full spectrum halide bulbs..It seemed to work well over the past year, where my new cattleya growths matched the previous greenhouse grown size bulbs. And had 25 out of 75 bloom and maybe 30 more currently in sheath...it is just expensive at 150 a month...i know leds put out a different color light, red and blue or white, which is supposed to be better for plants needs! why very few responders if any, have bloomed catts with led's is a mystery....i cant risk my expensive collection on different colored lights that have zero success rate to date..most experienced growers just graduate to greenhouses i guess....