I've intentionally let my GSP grow for two simple reasons it kills the purple star polyps and it looks cool 
 
However if I need to remove it I just use a broad flat screw driver and scrape where I don't want it and it works well but it does take some muscle power and occasional swear word 
		
	
		
		
		
		
			
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				 My aquarium is nothing but a smorgasbord for my cats.....
			  
		
		
		
		
	
		
		
	
	
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