What is in grow lighting?

On a sunny day the light from the sun is typically 5600-6500 kelvin. When it gets cloudy the kelvin temps go up into the 7-8's or even higher. Our tungsten lighting at home is usually always 3200k. Warmer since it's more pleasing to our eyes. Ever notice a daylight bulb at night will give you a headache, well it does me. I hate seeing people light their homes with daylight CFL's. It's not pretty. Anyway

We buy bulbs for our plants that try to match nature, daylight. Within one of your 5k bulbs the full spectrum is given off, some wasted as green light, the useful light energy red and blue is what's important. Grow bulbs usually target the red and blue spectrum only. We don't use just red and blue only since you don't want a red or blue lit tank. So we use the full spectrum bulbs that give off both beneficial and useless light for the plants but are typically calibrated to give off the most useful spectrum.

Next time your in a parking garage or your office take a moment to examine the light given off by a standard fluorescent bulb. They are typically in the 4-5k spectrum and usually you can see a ton of green given off, not flattering. It's easy to see when you look at a white wall. I've been noticing some of the newer fluorescent bulbs are becoming more flattering to our skin tones. They are adding more phosphorus and giving off much more magenta than they used to. Plant bulbs usually give off a lot of red. It's usually recommended to mix the high phosphorus magenta/red bulb with a standard daylight bulb to make up for the other colors in the spectrum needed i.e. blue.