Elution Study for Industrial Water Softener Systems

Have you noticed any of the following about your commercial or industrial water softener system and its water hardness?

  • You’re not getting the soft water you need
  • Your run times are not acceptable
  • Your water is intermittently hard

The bottom line is that your commercial or industrial water softener system may be working, but not as well as it should be. If this sounds like your situation, then maybe it’s time for an Elution Study by Industrial Water Solutions.

One of the most critical steps in the water softener regeneration process also happens to be one of the first places where problems occur. The Elution (ee-LOOT-shun) Step, or the point where calcium and magnesium ions are removed from the resin beds with a highly concentrated salt solution (NaCl), is one of the most critical steps in the regeneration process for industrial water softening systems. If any one of the three physical process variables involved in the process (velocity, concentration, and time) is not correct, then proper regeneration of your industrial water softener will not take place.  Accordingly, the ensuing regenerations will then result in reduced throughput, meaning lower efficiency in your operations.

There are two sampling points for an Elution Study:

  • Brine tank
  • Regenerant drain line going to the sewer

The Elution Study procedure involves measuring the concentration of brine in the brine tank using the Salometer.  The brine tank should be 90% to 100% saturated (that is, 90 to 100 Salometer degrees) at room temperature.  Samples are then drawn every two to three minutes and plotted on a graph.  Once the data points are connected to make a curve, a horizontal line is drawn at 30 Salometer degrees.

Ideally, there should be 25-30 minutes where the curve is above the 30 degree Salometer reading.  This is known as the 30/30 Rule where a solution of 30 Salometer degrees is in contact with the resin for 30 minutes.

Here are some of the graphs that may be experienced along with the associated issues in the water treatment system:


Factors that can adversely affect the elution curve include:

  • Not enough brine drawdown
  • Channeling of the resin bed.
  • Restricted brine line or eductor resulting in a slow brine draw.
  • Restricted distribution system.
  • Improper adjustment of brine rinse flowrate
  • Unsaturated brine in the brine tank.
  • Iron and/or dirt fouling of the zeolite bed
  • Insufficient zeolite bed depth (less than 24 inches, indicating loss of resin)

Conducting an Elution Study is an effective way to drill down, discover, investigate and solve water treatment issues.  This process takes time and special tools, resources that most property engineers just do not possess. Industrial Water Solutions has the experience, tools, skill and time to an Elution Study, identify any deficiencies, AND fix those deficiencies with the best corrective steps to ensure maximum throughput for your operational demands.   After all, our goal is to help you maximize your water softener ROI and reduce your costs.  One simple Elution Study can ensure your water regeneration system is operating at maximum efficiency with optimal throughput.

To schedule an Elution Study, call us at 800-820-9021 or send us an e-mail at info@industrialh2osolutions.com.

See our technical articles on industrial water systems for tips and troubleshooting of industrial water softeners, deionizers, reverse osmosis, filters, and more.

Questions? Contact Industrial Water Solutions at 800-820-9021 or info@industrialh2osolutions.com for: