Clarifiction on Kelven scale

[Hunter76]

Hello all,
I understand that the higher the Kelvin temp the higher the energy the bluer the color. My question is what is the benefit of the bluer color? To me blue light is high energy and penetrates the deepest. So what he major difference btw 7100K,10000K, and 20000K. I assume this helps to keep deep water corals do to the different energies and wavelengths. Whats a good compromise? IS it worth it to change from 7100K to 10000K?
Thanks for the clarification.
Scott

[trojanfish]

For your reading enjoyment... More info than you asked for, but the answers to your questions are in there...
http://www.animalnetwork.com/fish2/aqfm/1999/july/features/2/default.asp


tf

[horge]

Nice link trojanfish.

And Hunter, your general distillation of the Kelvin scale is correct. A hypothetical blackbody heated to X degrees Celsius will radiate a certain 'color' (sort of like when a bar of metal turns dull red, cherry red, orange up to yellow-white when heated. It would go up to blue if only it didn't vaporize prior). Any two blue bulbs of the same hue and tone generally earn the same Kelvin rating, regardless of the wattages involved.

There's a lot of debate over what the ideal wavelengths are for corals in general (let alone in specific). Still, if you're mimicking a reefcrest at about 1 metre depth, then a 7100K may serve.

I personally prefer the look of tanks using multi-wavelength lighting, providing high-Kelvin lamps, supplementing full daylight as well as yellow-lighting lamps.