Did they determine the rock has soaked up phosphate and copper? The reason I ask is I have some rock that's forty years old that's now in an sps tank with no issues. Unless a rock is going to leach out a lot of material the average water changes should take care of any small amount of phosphate that does leach out. Algae growing on the rock should be a pretty good indicator if the rock is harboring a lot of nutrients. I would expect an extended soak in ro water before reusing the rock would remove most of it. Randy not being a reef chemist I'll bow to your expertise in the matter but as I said before if I was really leery about the rock I'd just chunk it. Not worth the risk in the long run.



