Where does corrosive water come from?
Corrosive water is common in the Northwest and is caused by low pH, low alkalinity, and low TDS. The more pure the water is, the more corrosive the water becomes. When homes have corrosive water and copper piping, the water attacks the copper and causes it to oxidize, which leads to blue-green staining of fixtures throughout the house. Even more important, the copper piping will be thinned to the point of pin holes occurring, resulting in structural damage and increased risk of flooding.
With mildly corrosive water, a simple neutralizer tank that dissolves calcite into the water will raise hardness and TDS, effectively raising pH by .5-1 unit. With more corrosive water, a pH injection system using soda ash is most effective and gets the best results. It also has the benefit of being easy to control.