Today I received a Tunze Protein Skimmer that I purchased used on ebay. The protein skimmer is working but there is no foam going to the collection cup nor any coming out the outlet pipe. I am fully aware that there is a break in period with new protein skimmers but am unsure about a used protein skimmer. Also why is there no water coming out of the outlet pipe. The water sits about a inch from the top of the pipe. Is this normal?  
Jon
	
		
			
		
		
	
			
			Jon
 
					
				
