The Softening Process

The Basics

Water Softening is the term given to the removal of hardness causing ions such as Calcium, Magnesium and Iron from a source of water. Essentially, Industrial Water Softeners are comprised of two parts: a mineral tank and a brine (salt) tank. The mineral tank houses the ion-exchange resin, which is positively charged with Sodium ions, and is the place where ion exchange occurs. As feed water passes over the Sodium-charged resin, saturated with Calcium and Magnesium, the latter is exchanged for the former in a physical reaction. After some time, the ion-exchange media of Industrial Water Softeners becomes saturated with the hardness causing ions, and requires regeneration. This is the reverse of water softening, in that salt water from the brine tank is drawn to flush the Calcium and Magnesium concentrated water into drain. The 4 basic modes of the control valve of any Industrial Water Softener are Service, By-pass, Brine draw and Regeneration.

Single mineral tank vs. Twin-alternating models

Nearly all manufacturers of Industrial Water Softeners produce models with both single mineral tanks as well as double mineral tanks. There exist two major differences between the single and double tank models. They are: 1) The single mineral tank model of the same size has half the softening capacity, and 2) The double mineral tank model allows for continuous soft water flow because of it’s different regeneration cycle.


Single Mineral Tank Model

  • To handle the same hardness conditions, the single mineral tank Industrial Water Softener needs to be twice as large as each individual mineral tank of the double mineral tank Industrial Water Softener
  • Regeneration causes the Industrial Water Softener to be put into by-pass mode, thereby providing non-continuous soft water
  • Typically takes up less space than a similar capacity twin-alternating model (double tank Industrial Water Softener)
  • Regenerates less often than comparable double tank models

Twin-alternating (double mineral tank) Model

  • Provides non-stop, continuous flow of soft water
  • Most Industrial Water Softeners tend to be twin-alternating because many industrial processes run 24 hours/day
  • Easier to maintain and repair, since each mineral tank is relatively smaller and can be swapped out for a temporary replacement
  • These Industrial Water Softeners are much simpler to install because each unit weighs half as much as the larger single mineral tank model of comparable capacity