This is our high capacity resin can can be used in any water softener system. We also have this listed in the 1/2 cu. ft. bags see our other listings or ebay store using the links at the right. The standard 9" tank uses 1 cu. ft., the 10" diameter tank uses 1.5 cu. ft. so you would need a 1/2 and a full cu. ft. order. This is a high-capacity, bead-form, conventional gel polystyrene sulfonate cation exchange resin ready for use in household or industrial water conditioning equipment. It removes hardness ions, e.g. calcium and magnesium, replacing them with sodium ions. When the resin bed is exhausted so that the hardness ions begin to break through in the effluent, capacity is restored by regeneration with common salt. The capacity obtained depends largely on the amount of salt used in the regeneration. This resin is also capable of removing in the same way dissolved iron, manganese, and also suspended matter by virtue of the filtering action of the bed. This resin is in compliance with the U. S. Food and Drugs Code of the Federal Regulations section 21 paragraph 173.25. Polymer Matrix Structure 8% Polystyrene crosslinked with Divinylbenzene Physical Form and Appearance Clear spherical beads Whole Bead Count 90% min. Functional Groups Polystyrene sulfonate Ionic Form (as shipped) Na Shipping Weight, approx. 850 g/l (53 lb./ft.3) Screen SizeBritish Standard ScreenU.S. Standard Screen 14-52 mesh, wet16-50 mesh, wet Particle Size Range _1.2 mm