9" X 48" NSF Certified polyglass tank with base, lifetime warranty. Pentair/Fleck 5600 12 Day Timer control valve, 5 Year Warranty.Stainless Steel by-pass valve, 3/4" or 1".Custom blend of Calcite and Corosex depending on pH value.1/8" X 1/16" Coarse gravel.9" X 48" pH Neutralizer with a combination of Calcite/Corosex is used to raise pH level to 7.0 or slightly above for water of 6.2 to 6.8pH with a flow rate of 8 gallons per minute (GPM). Waters with Higher flow rates and lower pH will need a larger tank.