By the way, how long is your tank?  If it's 48" and you're putting the LED's on a 36" heatsink that should be fine.  I mean, obviously the ends of the tank won't be lit as well but for most tank layouts that's fine - it either gives less illumination in an area where you're really not growing anything or gives you a zone where you can safely grow less light-loving corals. 
		
	
		
		
		
		
		
	
		
		
	
	
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