I have a 20K XB on an 8.6g and it's great. The optics really distribute and blend the light well. I have had 50/50 and actinic Reefbrites, and while I liked them, the BML light is far superior in build and brighter. With the Reefbrite 50/50 the color separation was noticeable. One side of the tank was bluer. The Reefbrite actinic was nice, but as mentioned above, it's only royal blues.