Can someone please identify the brown and rust colored what looks like some type of macro algae (see attached pictures) that has slowly started to cover my rock?  Secondly, if someone can identify it, is it going to be harmful if left unchecked?  Third, unless it is extremely beneficial, I would prefer to have it removed, so is there a safe and easy way to do that without totally disrupting my rock structure?  Any help is appreciated.
		
		
	
	
		 
	
		 
	
		 
	
				
			 
	 
 
		 
 
		 
 
		