is there anybody out there running the 15k XM's? sure would like to see the color rendition. i heard you can run these with no attinic.???????
We are, and I've never been happier with the coloration of a bulb than I have on these. NO actinic supplimentation whatsoever, and the color is absolutely perfect. Corals and softies that used to have a yellowish-brown color in the 75G (XM 10ks) now POP with coloration. As far as growth - we are getting better growth with these 400W 15ks than we were with the XM 10ks! I love them!!

I think Chris posted a few pics when we first installed the 15ks - pics don't do them justice, as they take on a much bluer hue through the pics...to the eye they look to be a nice crisp white with a hint of blue. There have been a few people that have seen the tank in person, and they liked they way they looked.

W.