I have never used GFO. I use ROWAPhos and Chemi-pure elite.  
I should change up my RowaPhos tonight and do a water change.  
 
I will test my PHOS agaon wioth my Hanna checker.  
 
I also did buy SeaChem Phosguard but I have not used it yet.. Not really sure the amount to use or the best way to use it. 
 
 
I run my Rowaphos in a TLF 150 reactor. 
		
	
		
		
		
		
			
		
		
		
		
	
		
		
	
	
	 |