do you have any better pics of the powder blue he looks very pale in the ones you posted.
I examined my powder blue very closely last night and I really think my pics I took yesterday had a lot to do with making the fish appear somewhat pale under very intense, 10 k lights and with my camera flash going off so close. When I observed the fish again last night, she had a very dark, black face and mouth area, and the main body of the fish showed a soft blue color, which is normal for powder blues. Ironically, the picture displayed in the Marine Depot catalog for Powder Blue tangs looks almost identical in shape and color, to the same pics I posted yesterday of my pb, go figure!
Have you encountered any compatibility issues with placing your achilles tang in the same aquarium with a chocolate/mimic tang? I also have a mimic tang, but was unsure whether these two acanthurus tangs could be housed together in the same system without fighting, etc.