I'd probably set-up a small frag tank.  Good clean water in a brand new ten gallon tank.  If they survive it rules out enviromental issues in or around your house,  If they don't survive.. back to square one, but at least you have ruled out one or more possablilities 
		
	
		
		
		
		
			
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				Robb
			 
		
		
		
		
	
		
		
	
	
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