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			#1  
			
			
			
			
			
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|   I would just lift those rocks out one by one and pick all the valonia off by hand and then put the rocks back in. | 
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			#2  
			
			
			
			
			
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|   Yup, pretty much. After picking them off, you can give the rock a quick toothbrush scrub in a peroxide 4% / nsw bath. |