An ion exchange resin with a reticular porous matrix that makes it effective for removing colloids and bacteria from process streams, as well as dissolved anions. It is especially useful for preventing colloidal and organic fouling of mixed-bed resins and premature clogging of final filters.Macroreticular resins are made of two continuous phases - a continuous pore phase and a continuous gel polymeric phase. The polymeric phase is structurally composed of small spherical microgel particles agglomerated together to form clusters, which, in turn, are fastened together at the interfaces and form interconnecting pores. The surface area arises from the exposed surface of the microgel glued together into clusters. Macroreticular ion exchange resins can be made with different surface areas ranging from 7 to 1500 m2/g, and average pore diameters ranging from 50 to 1,000,000 A.