5 lbs Mixed Bed Ion Exchange 0 ppm DI resin, RO aquarium Five pounds of resin is enough to refill an 2″x10″ in-line refillable filter housing about 10 times or 2.5″x10″ refillable filter (for standard 10″ housing) about 7 times. Excellent High-capacity, mixed bed, Industrial grade media for deionization of water for industrial, aquatic, and other water treatment applications. Safe for all machines, aquariums: Creates consistent, safe, ultra-pure water for car washing and window cleaning etc…. 5 lbs Mixed Bed Ion Exchange 0 ppm DI resin, RO aquarium DI mixed Bed Resin Water filter – Deionization water filter TDS meter is required to measure the life of the resin. DI filter ( Mix Bed Resin ) named as de-ionization stage Demineralization Resin used to produce 99.99% pure water by simply attaching this convenient deionization filter with RO unit. Convenient post RO filtration DI unit (RO/DI unit) provides crucial supplemental filtration to remove most impurities for pure polished product water. Excellent in areas with hard water. Produce 99.99% pure water. It will give you 0 ppm TDS, Conductivity attainable less than 0.1uS/cm or resistivity of close to 18 meg.ohm. Simply DI filter removes remaining of dissolved solids after RO system.