Thanks everyone for your input!  It sounds like adding a refugium to my system is a good idea.  I've already decided to replace my sump with a bigger tank and now I'll add a separate refugium tank as well.   
 
Given the space I have available, the best option seems to be to place the refugium right next to my sump.  My plan is to set up a small pump to pump from my sump into the refugium with an overflow back to the sump. 
 
How does that sound? 
		
	
		
		
		
		
		
	
		
		
	
	
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