Resin Longevity: Expected Life Span of Ion Exchange Resins

The operating life of ion exchange resin depends on several factors. Degradation of resin can be attributed to mechanical, osmotic or thermal shock; temperature; dissolved oxygen; and chemical oxidation due to attack of chemical like chlorine.

DI resins usually last for many years. In general, cation resin for water softening and demineralization may last 5 to 10 years. Anion resins last anywhere from 3 to 5 years and are dependent on operational conditions. Some of the resin beads break during the swell cycle when regenerating. Moreover, resin life is partially dependent on the number of regenerations and partially on the quantity of oxidizers passed through the column.

You can prolong the life of your resin provided the following circumstances are met:

- Adequate pre-treatment is in place, i.e. organics and suspended solids are removed and kept to minimum.

- Chlorine content in feed water is zero to undetected (determined through water quality analysis). In the presence of chlorine or any oxidant, ion exchange resins will breakdown prematurely.


- Low levels of iron in feed water. Cation resin removes ferrous iron but removing the iron off of the resin is a difficult which will result in loss of capacity overtime due to iron being embedded into the cation bead.

- There is no sudden and significant increase in raw water quality that would affect the performance of pre-treatment system which will in turn affect the quality of feed water to the ion exchange resin. Ion exchange resin system is designed based on feed water quality, therefore include safety factor in the design to handle occasional “spikes” in feed water quality.


- Operators are aware of the proper operation and maintenance of ion exchange system.

Because many variables and factors are involved, it's difficult to predict the life span of a resin and we can only provide you with what is the expected life span given ideal conditions; in critical applications it’s best to start analyzing and benchmarking the resin at least once per year.