I really think that the dogma that 65K bulbs cause increase growth compared to other kelvin bulbs is a gray area, and that it is species specific. Corals growing in 10 feet of water are going to be much more adapted to the yellow spectrum than ones at 40 feet, where mostly blue spectra light will reach (longer wavelength, thus will penetrate water better).
Some review:
Photosynthesis 101:
Chlorophyll a is stimulated at 400-490 nm, chlorophyll b at 450-470nm with an additional peaks for both in the 650-670nm range
http://bio.winona.edu/berg/ILLUST/fig15-5.jpg
Chlorophyll absorbs and reflects light which we see as color and fluorescence.
Chlorophyll absorbs light largely in the blue and red portions of the electromagnetic spectrum.
Chlorophyll reflects and transmits light in the green and yellow portions of the spectrum.
Accessory pigments, such as carotenes, phycobilins and xanthophylls, absorb light energy in portions of the spectrum where chlorophyll cannot and transfer that energy to chlorophyll. Light energy is transferred amongst pigments as the energy of resonance.
When light is absorbed electrons move up an excitation state. This transition is not a gradual one, but rather electrons move up in a quantum jump. If the electron is not captured by some other compound, the electron looses energy and falls down to its ground state. Some of the energy is lost as heat, but some is re-emitted as a longer wavelength light. This phenomenon is called "fluorescence."
So it all really depends on the organisms ability to synthesize the different light capturing compounds and the ratio of the two chlorophyll that dictates its color and ability to synthesis sugar from light.
[ January 30, 2005, 01:26 PM: Message edited by: solbby ]
The hamilton 14k is also a good bulb but doesn't give your corals that fluorescent look like the AC's do. Nick what ballast are you running the XM's on?
