The fluval will contribute to nitrates, get rid of it. You're feeding way too much, IMO, for a time when you're having cyano problems. I'd feed some dry pellets once a day, mysis maybe once a week, sparingly. If you have too many fish, then yes, that can contribute.  
What type of water change schedule are you using? 
		
	
		
		
		
		
			
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				Brad
			 
		
		
		
		
	
		
		
	
	
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