not much algae on live rock

[goldie]

I am new to this but I am wondering how much algae should there be on my live rock? The piece that is closest to my more powerful powerhead is pretty white while the rest has more of a red color to it. There is also a spot with some green algae that looks like hair. Should I move my powerheads a bit? How do I know what it good algae and what is bad?