Cation Resin

• The color of the resin has no impact on performance. 
  • Black cation is available at a premium.
• Cation resin is available as 6%, 8% & 10% crosslink.  Higher crosslinked 12-15% cation resins are manufactured for special applications. The higher the crosslink, the higher the cost.  A great article by ion exchange expert, Chubb Michaud, gets into the details of crosslinking. http://wcponline.com/2011/06/07/role-cross-linking-ion-exchange-resins/
  • Chubb’s highlights:
    • Higher cross-linking means higher density with more plastic and less water.
    • Higher cross-linking produces a tougher matrix that is more resistant to both chemical oxidation and physical breakdown.
    • Drawbacks include higher costs and slower kinetics (not a good thing for cold water). Although higher cross-linked resins have a higher total capacity, the kinetics in colder water may actually result in a lower operating capacity than a lower cross-linked resin and prove to be an incorrect choice.
• How long does resin last?
  • In non-chlorinated water 6% resin lasts ~ 8 to 10 years; 8% much longer. In general, the resin will wear out in the same time frame as the other parts of the softener – the valve, tank, brine tank, etc.
  • For iron removal applications we recommend using a phosphoric acid drip to keep the resin bed clean so it lasts longer.
• Precautions
  • Use sodium form cation not hydrogen form.
  • Don’t store outside if there is the possibility of repeated freezing and thawing.
  • Don’t overfeed chlorine. Consider an activated carbon filter as pre-treatment.

Urbans Aqua stocks Purolite & Thermax cation resin for quick shipment.

Our rules of thumb when applying these resins:

• 6% – Residential use on well water without chlorine.
• 8% – Residential or Commercial/Industrial well on city water where 1 ppm or less of chlorine.
• 10% – Residential or Commercial/Industrial well on city water where chlorine/chloramine levels are greater than 1 ppm. Also used where there is a combination of hot water and oxidants- chlorine or chloramine).

Installation of an activated carbon filter ahead of the softener to remove the chlorine or chloramine will prolong the life of the resin.

Sodium (Na+) strong base cation resin is commonly used for household, commercial and industrial water softening applications. According to the Water Quality Association, water hardness in the United States ranges from 1 to 350 grains (gpg) per gallon or 17.1 to 5,985 ppm.   However, most waters range between 3 and 50 gpg.   USGS Water Quality Information

Softening with cation resin is a simple exchange function. The resin bead is negatively charged and attracts positive ions. When supplied in the sodium form (Na+) the resin will exchange sodium ions for hardness ions – calcium and magnesium. The bead is more strongly attracted to these ions and readily exchanges with the sodium. Once the resin is exhausted it is regenerated with a brine solution (NaCl). The brine overwhelms and releases the calcium and magnesium from the bead. The resin is converted back to the sodium form and ready for re-use.

• Free chlorine levels above 0.5ppm or any oxidant decrosslink and shorten cation resin life.  Dow Resins Recommended maximum free chlorine levels
• In applications with high chlorine levels and temperature use a 10% crosslinked gel or macroporous resin.

Urbans Aqua stocks:

• Purolite C-100Na C100 Cation Resin Product Data Sheet
• Purolite SSTC6000E
• Purolite C-100EFM Purolite C100EFM
• Thermax Tulsion T42Na Resin Cation TULSION T-42 Na N & Tulsion T52Na Resin Cation TULSION T-52 Na N
• These cation resins are suitable for residential, commercial and industrial applications.