9" X 48" NSF Certified polyglass tank with base, lifetime warranty.Pentair/Fleck 5600 Control Valve, 5 Year control valve warranty.Calcite media used to balance pH levels to 71/8" X 1/16" Coarse gravel.Calcite media is used to neutralize pH levels that are acidic (pH levels less than 7). Calcite is calcium carbonate which automatically self-limits the dissolve and stops at a pH level of 7.9X 48" pH Neutralizer has a flow rate of 10 gallons per minute (GPM).