Why does my fish look "salted"

[pktech]

in the morning & within a few hours, its clear? Noob question, but I want to hear what the board thinks ...

 

[Chris27]

What type of fish and where does it sleep?

 

[pktech]

collare butterfly & probably sleeps in the live rock - scares me when I first see it, but it within hours it's gone - it doesn't happen everyday, but enough for me to notice... just asking if anyone else sees the same thing from time to time ...