Acidic waters on contact with calcite slowly dissolve the calcium carbonate media to raise the pH which reduced the potential leaching of copper, lead and other metals found in typical plumbing systems. Periodic backwashing will prevent packing and maintain high service flow rates. Depending on pH and service flow, the calcite bed will have to be periodically added to as the dissolved calcite depletes. As the xalcite calcium carbonate neutralizes the water, it will increase hardness and a softener may become necessary after the neutralizing filter.