I have two waterers.  One is a 5 gallon buket and the other is a metal one from the store.  I am noticing when I clean them out to put freash water in them they have green alge in them.  Mostly around the lid of the 5 gallon bucket.  It is white so I can see it better but it is in both.  Is there anything I can add to the water that will keep that from happening?  That will keep the water clean.  I worry when I am gone for a week and they don't get cleaned as often.
	
		
			
		
		
	
				
			 
	 
 
		 
			
		
		
		
	
	
			
		 
	 
 
		 
 
		 
 
		 
			
		
		
		
	
	
			
		 
 
		 
 
		 
 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		