View Full Version : Spectrum of GrowLights: How the sun's energy affects plants & how to produce it...

12-10-2009, 02:55 PM
I'd love it if we could compile a bunch of information here regarding the different parts of light's spectrum and how they affect a plant's growth.
Also, provide suggestions as to what mixture of lights one can use to produce a truly complete spectrum.

Here's all I know...

Blue is good for trunk/stem and leave/vegetable growth, right?

Red is good for flowering, right?

What about yellow?

I imagine that UV rays could cause the plant's defense mechanisms to kick in, possibly creating desirable results for us, right?

What else is there to the spectrum and how might that affect the plant's growth?

How does one produce the different parts of the spectrum and what are the percentages of the mixture for the spectrum that one might want in the different stages of a plant's life?

I suppose I've heard that Metal Halide lamps are for blue light, but do they produce any UV, reds, or yellows?
I suppose I've hear that High Pressure Sodium lamps are for red light, but do they produce any UV, blues, or yellows?