Alkalinity is a measure of the capacity of water to neutralize acids. Alkalinity is primarily due to the presence of bicarbonate, carbonate, and hydroxide ions. Alkalinity acts as a pH buffer to deactivate acidity. Water with high alkalinity may have an offensive taste. These filters are tanks filled with a media blend of calcium and magnesium carbonates made from naturally occurring minerals. This media slowly dissolves into the water, raising the pH and making it less corrosive. One of the most important benefits of alkaline water (besides increasing the pH) is that it lowers Oxidation Reduction Potential (ORP).