The Tufa rock I have is sand colored.  Its not lava rock...I did a bunch of reasearch prior to buying it and deternined it would be safe.  I know my setup is not ideal for a reef tank.  I hope in a few months it will stabilize and be an attractive marine fish tank.... 
 
 
Kennyv 
		
	
		
		
		
		
		
	
		
		
	
	
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