The sticker on the membrane actually says 'run for 2 hours'.  That's probably a very conservative warning. I ran 6-7 tanks worth over a day just to be on the safe side.  I didn't want a stomache ache (as the label warns...) lol. 
		
	
		
		
		
		
			
				__________________ 
				George
			 
		
		
		
		
	
		
			
			
			
			
			
			
			
			
			
				
			
			
		 
		
	
	
	 |