If it's a really white sebae anemone, it likely spewed all of its zooxanthellae before you got it. Typically this type of anemone does not recover from this and dies within a year of captivity.  
 
Do you know which type of sebae it is, malu or cripa? Are you able to take a picture? 
		
	
		
		
		
		
			
		
		
		
		
	
		
		
	
	
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