Well-water is often acidic / not “pH neutral” (~7.0 – 7.4 pH) and must be corrected (“neutralized) to avoid leaching copper and lead from copper/soldered pipes and otherwise damaging plumbing. Acidic well-water is often “neutralized” using calcite. Calcite is a naturally occurring calcium carbonate media. One of the advantages of Calcite is its self-limiting property. When properly applied, it corrects pH only enough to reach a non-corrosive equilibrium; it does not overcorrect under normal conditions.
Upon contact with calcite, acidic water slowly dissolves the calcium carbonate to raise the pH which reduces potential leaching of copper, lead and other metals found in typical plumbing systems. Periodic backwashing of the calcite medium in the neutralizer tank will prevent packing, reclassify the bed and maintain high service rates. Depending on pH, water chemistry and service flow, the Calcite bed must be periodically replenished with fresh material as the Calcite is depleted.
As the Calcite’s calcium carbonate neutralizes the water, it will increase “hardness” (mineral content dissolved in water) and a softener may become necessary after the neutralizing filter. A water-softener tank that filters calcium ions through zeolite medium (that is routinely backwashed with a salt/brine solution) usually follows a pH neutralizer.