1/2 cu. ft. bag of fine mesh resin CATION Standard and Fine Mesh Resins Nelsen CATION Standard and Fine Mesh resin is a high capacity, conventional gel polystyrene strong acid cation exchange resin designed for use in residential or industrial water softening equipment. Cation resin in sodium form removes hardness ions such as calcium and magnesium by replacing them with sodium. When the resin bed is exhausted the hardness ions begin to pass through the bed. Functionality is returned by regeneration with concentrated sodium or potassium chloride solution. The capacity obtained depends largely on the amount of salt used in the regeneration. Typically 15 lbs of chemical per ft3 is used to obtain maximum capacity of up to 33,000 grains per ft3. C108DQ-Na resin is rigorously treated before shipping to meet all NSF- 44 standards requirements.  Must use gravel bedding and fine mesh baskets when using this resin