replying to KB, Cal wrote:
hi, I too am in this mess, first wash of the limestone with Oxalic Acid
removed the stains but unfortunately they are back after a few weeks, as
mentioned in other responses they are less intense BUT still there. I am now
on the second wash with the Oxalic Acid so hopefully this will reduce it
further, otherwise I am going to keep the process going and hope that it helps


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