Many people have a water softener system to remove the dissolved minerals, including calcium, magnesium, and iron. This system will treat all the water coming into the home to protect the plumbing system, water using appliances, and even our health. The most reliable method is known as ion exchange, and to facilitate this process a softener resin media is required. In this article, we will take a closer look at what softener resin is made from and how it works in a water softener.

An Ion-Exchange Water Softener Primer

Around 85% of homes in the U.S. are supplied with water that’s classified as “hard.” This water contains elevated levels of dissolved minerals that must be removed to make the water “soft” and easier to use. An ion-exchange water softener is the preferred method for many homes and businesses. It’s effective, reliable, easy to understand and aside from a little maintenance from time to time, it’s relatively hassle-free.

An ion exchange water system consists of two tanks that are connected together. The first tank is where the water softening takes place; this media tank is filled with resin beads that facilitate the ion exchange process. The second tank is the brine tank, which is filled with a solution of water and salt. Certain advanced models may have a pre-filter to remove silt and other debris to protect the system from potential damage. Some media tanks contain loose resin beads, and others have a simple cartridge replacement system.

What is Water Softener Resin?

The ion exchange process cannot take place with water softener resin that’s charged with salt. The material typically used for the resin is called crosslinked polystyrene divinylbenzene or polystyrene sulfonate. This is a food-safe insoluble material that has been approved for use in water treatment by the U.S. FDA. The size of these resin beads can vary from 0-3 mm up to 1.2mm and the most common size is just under 1mm. They come in various colors, including white, amber, dark brown, brown/yellow, and light tan. They are known as cation resins, and they have a greater surface area designed to trap dissolved mineral ions. Aside from water softening, these resins are used in certain agricultural, manufacturing, and pharmaceutical decontamination processes.

How Does the Ion-Exchange Process Work?

The resin media beads have a negative charge, and the mineral ions have a positive charge. When the water flows through the resin media tank, the mineral ions are attracted to the resin beads. As the mineral ions adhere to the resin beads, the ion exchange takes place, and the salt ions from the beads are transferred to the water. The amount of resin used in a water softener will vary depending on the hardness of the water. Over time the resin bead surfaces are coated with a layer of mineral ions which degrades their performance. During the regeneration cycle, the surface of the resin beads is flushed clean with brine from the brine tank. This cleans the surfaces and adds a fresh layer of salt for the next series of ion exchange processes.

If you want to install a water softener or schedule some essential maintenance for your system, contact your local water treatment specialist.

By EcoWater Systems.
EcoWater Systems of Nebraska is the largest water treatment company in the state and is a member of Water Quality Association.