Iron corrosion cause reddish or brown water and also imparts a metallic taste. Zinc corrosion does not usually discolor the water, but can also cause a metallic taste. All waters are corrosive to some degree, and a water's corrosive character depends on its physical and chemical constituents. For instance, water that may corrode iron pipe may not be as corrosive to copper pipe. Often these waters are of high quality and are low in buffering calcium minerals, but are high in dissolved carbon-dioxide gas, which can cause the low pH or acidity.
Treatment is accomplished by neutralizing the water with the use of an automatic neutralizer.
These water filter tanks are filled with a blend of calcium and magnesium carbonates made from naturally occurring minerals, which dissolve into the water, making it less corrosive. Other methods commonly used are pH adjustment by injecting soda ash or a sodium hydroxide solution into the water upstream of a holding or retention tank. Also see Acid Water . Corrosion can often be treated by raising the pH of the water, by adding phosphate in various forms into the water to seal off the corroding piping, or by using cathodic protection. Corrosion can be complicated to treat, especially if the water does not appear to be corrosive from a chemistry standpoint.