Quote:
	
	
		| 
			
				 How come you can get more GPH out of a pump if you increase the pipe diameter? Does that still hold true if you say run 2 inch all the way then go down to 1 inch at the end?
			
		 | 
	
	
 Bringing your 2" line down to a 1" will reduce your entire flow to 1".
 
You would have to have the pipe and fittings 2" in order to not restrict your flow and essentially choke off your flow.