blue tang ich?

[bellorusha]

2 days ago I notice that blue tang has some dots on his body. they are not white so I did not think it is ich. It is eathing normal. Swimming normal. But they not comming off for a few days now.
the dots much bigger then Black ich
http://www.fishbase.org/diseases/DisPic/BlksptD1.jpg


Is it ich?

P.S. I did put 40 pounds of new live rocks a week ago.

thanks.