Naturally occuring media for neutralization of acidic water. Helps resolve problems with blue/green staining and pin holes in copper pipes. Amount of media required can be determined by tank size: -8″x44″ 0.5 ft³ Tank – (1 bag) -9″x48″ 1 ft³ Tank – (2 bags) -10″x54″ 1.5 ft³ Tank – (3 bags) -12″x48″ 2 ft³ Tank – (4 bags) -13″x54″ 3 ft³ Tank – (6 bags). If more than 1/2 cubic foot is needed, enter total number of 1/2 pound bags in the quantity. Example…you need 1.5 cubic feet, enter your quantity as three (see tank sizes and amount needed above).