Anion Resin Applications

Anion resin is commonly integrated into water treatment systems to reduce tannin, nitrates or alkalinity.

Urbans Aqua stocks specialty anion resin for quick shipment.

Visit our PDF Library for technical specifications and product manuals on cation resins.

Visit our SDS Library for safety data sheets on cation resins.

In Stock Brands:

Purolite Anion Resin  Thermax Anion ResinResinTech Anion Resin

Anion exchange resin has a positively charged matrix with exchangeable negative ions (anions). Positively charged ions are fixed and permanently attached. Negatively charged replaceable ions, usually chloride, keep the resin electrically neutral. Because the bead is positively charged only negatively charged ions are attracted or exchanged. For water treatment purposes anion resin comes in the chloride form (Cl-) or hydroxide form (OH).

Anion resin is usually light in color. However, color variation among brands has no impact on its performance. For drinking water applications look for WQA Gold Seal or NSF certified products.

All anion resins are adversely impacted by chlorine – Dow Resins Recommended maximum free chlorine levels

Common Anion Resin Applications


Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that includes PFOA, PFOS, GenX, and many other chemicals. To address this emerging contaminant Purolite has developed a new line of ion exchange resins.

According to Purolite, a properly designed PFAS reduction system should last longer and use less floor space than an equivalent activated carbon system.  This is especially true with larger flow rate applications.


Design & Installation


Tannin Reduction

Tannin, also referred to as TOC (total organic carbon), is a catch all term to describe water which is not clear.  TanninWater with Tannin water may have iron or color bodies in it. The color tainted water may come or go as it is seasonally affected.  For successful outcomes consultation with Urbans Aqua professionals is strongly suggested.


Although unseen, the incidence of nitrate contaminated water is rising because of past agricultural practices.


Used to reduce alkalinity. “Alkalinity is not the same as pH because water doesn’t not have to be strongly basic (high pH) to have high alkalinity.” (WQA Glossary of Terms Fourth Edition © 2000)


Strong Acid Cation in the hydrogen form (H+) in combination with strong base anion (SBA) in the hydroxide form (OH), is most often used for demineralization processes such as portable exchange tank (PEDI) operations. In this case, the hydrogen is exchanged for calcium, magnesium and sodium. (For more information please refer to section on demineralization for portable DI exchange operations.)

Links to Resin Specifications & Engineering Bulletins:

Resin Anion Overview Dow Ion Exchange Resins Anion Resins Odor

Resin Anion Overview Dow Ion Exchange Resins Type 1 and Type 2 Strong Base Anion Resins Differences

Resin Overview Dealkalization & Anion SBA Purolite A300 Type 2 Gel

Resin Overview Dealkalization SBA Purolite A300E Type 2 Gel

Resin Overview Nitrate Selective SBA Purolite A520E Type 1 Macro

Resin Overview Resin Anion SBA PFA400 Type 1 Gel

Resin Overview Anion SBA Purolite A400 Type 1 Gel

Resin Overview Anion SBA Purolite A-400OH Type 1 Gel

Resin Overview Tannin Reduction SBA Purolite A850 Polyacrylic Gel

Resin Overview Tannin Reduction SBA Purolite A860 Polyacrylic Macro

Resin Overview Tannin Reduction SBA Purolite A502P Macro Type 1

Resin Overview Tannin Reduction SBA Purolite Tanex Type 1 Macro

Urbans Aqua is a stocking wholesaler of Residential & Commercial Water Treatment Equipment and supplies including Ion Exchange Resin; Calgon & Jacobi Activated Carbon; Filterag Plus; GreensandPlus; Pyrolox Advantage; KDF; Birm; Sand/Gravel; Clack, Fleck & AqMatic valves; Stenner Pumps & Parts. 

We work exclusively with water treatment dealers.