If you want the coralline to survive you will need to have light over it.  Using just actinics seems to speed up coralline growth and hinder algae.  I would do 100% waterchanges every couple weeks or so depending on the nutrient level in the water. 
		
	
		
		
		
		
			
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				~ Mindy 
 
SPS fanatic. 
			 
		
		
		
		
	
		
		
	
	
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