How do I remove this level of scale from my pool wall. Its caked around the entire pool. I showed the photo to pinch-a-penny and they told me its calcium deposit, and sold me a suncoat "Ultimate metal control" product. I have already gone through 1 quart with daily scrubbing to no result. The previous owner of the home did not maintain the pool well and now I am left with dealing with the residuals. Is there any way to get rid of this stuff?

