what an amazing difference in color patterns! i was running 2~10k ushios above my reef, and am in the process of building a wooden canopy to hold 3 metal halides, 2~250w and 1~175. i got the most of the retrofit parts in yesterday, and decide to see how the 20k bulbs lite up the reef. and i am amazed at the change! so i'll be running 2~250w 20kXD and 1~175w 10kXDE which will be supplied by a 150whqi ballast.
8)