Thanx for the information Mike 
for my build I am a little confused about the reasoning behind the need of different diameter chamber and neck comparing to the size of the pump,which I think will be using a laguna 2400 with a modified volute and using stainless steel mesh.Which I think if its done right it should pull out of max 100W near if not more 4000lph of air and about 8000lph of water. 
		
	
		
		
		
		
			
		
		
		
		
	
		
		
	
	
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