Larry,
I don't think that there is a link to that information. I remember way back, when we were discussing lighting gels, sending you a thread from the reefkeepers mailing list where Sandy Cohen, specifically said that he had been growing corals succssfully under 4300K bulbs. He also spoke of using the gels to alter the light, but found it cumbersome because he was using painted glass instead of the plastic gels. Oh and BTW, the gels solve the problem with heat. They are designed to be placed within 10" of a 1000W halogen bulb. They are safe up to some crazy temperature (600+ degrees C). The heat stays behind the gel.
Gannet,
Please don't take this as a flame, that's not my style. I do however believe that if reefers 10 years ago listened when statments like:
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>. Lighting is a solved problem in reefkeeping <HR></BLOCKQUOTE>
were made, then we wouldn't be where we are now. I think that the lighting industry is evolving just like any other. Halogen bulbs are becoming very popular for a number of lighting applications from car headlights to building lighting. When someone questions the use of a technology it can only help us all. I say push the limits of what is accepted, and find out what is necessary and what isn't. Reefkeeping has just begun... we really have no idea how to do this thing right, yet. In ten years reefers are gonna look back and say, I can't believe they used to do that... kinda like we do now with things like wet/drys. You are more than welcome to your opinion... but please respect that others don't necessarily concur, and that when you make stagment statements, you aren't helping. The idea here is to further our collective understanding. You are probally thinking; "Well you are entitled to your opinion, but I know I'm right.", but if that were true, then people like Mr. Cohen wouldn't be changing the way all of us think about light requirements.
~ignatz