Calcite Cartridge 10" Filter Acid Neutralization for Alkaline Water Alkaline Water Cartridge. Acid Neutralizer Calcite Filter Cartridge Fits most industry standard 10-Inch in line filter housings. Dimensions: 9.75" x 2.5. Designed to be used in most standard sized RO systems and countertop filters. High Purity Calcium Carbonate (Calcite) Media. Capacity of up to 100,000 gallons pH Range of 5-9. This calcite media will only be activated upon by acidic waters. It will have little effect on neutral or alkaline waters. Will raise the pH of RO permeate water to make it less corrosive on copper piping. Food grade for food and beverages