The Commercial Potassium Permanganate tank (18"x33") is used with a filter containing Manganese Greensand. A recommended dose of 2-4 ounces of Potassium Permanganate per cubic foot of Manganese Greensand is suggested for regeneration. The tank has a liquid capacity of 20 gallons. 1.) 18" x 33" Brine Tank w/Salt Grid 2.) Pad on top of Grid 3.) Brass 2300 Safety/Float Assembly 4.) Overflow Elbow (Side of the Tank)