Yeah, I saw mention of those as well but had no idea what they were. I just went back to the thread and I believe it was yours (I recognized Pepper's house). Sarina's link seems to be dead now so I couldn't get the info on the metal halides. You're a step ahead of me on those. Is this what you're looking into? http://www.cp-lighting.co.uk/Lamps/70W-Iwasaki-Colour-Arc-PAR36 The limited charts I've seen seem to follow natural sunlight pretty well. I'm not sure I have the tools to properly test this though (I have only a 6.5 Solarmeter). Encouraging, but I'd want to see more data before putting it into use.