That's what I would do as well.  Get some 24x18x9 tanks made up.  4 stacked on top of each other, each tank draining into the tank below it and finally into a common sump where you can put your filter socks, heaters, UV, whatever and all run on one pump (like a Mag 18 depending on height of the rack). 
		
	
		
		
		
		
		
	
		
		
	
	
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