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					Originally Posted by  Titus99
					 
				 
				It just cal carb from hot springs. Though its a softer stone it will not disolve in tank. So I've read. The whiter the stone the less impurities. I read several threads on reef tank of people using it without issue 
			
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 Those travertine tiles you have are the tumbled stone. I wonder if the filled and honed travertine would be safe as well?