Water Softeners: How They Work and the Different Types

adding salt to water softener

A water softener is a device that is designed to solve hard water problems. If you don’t know what hard water is, it’s simply water that contains dissolved minerals such as manganese, magnesium carbonate, and calcium, magnesium carbonate. 

If you find that your shampoo or soap doesn’t lather well with water, bathtub has a ring, dishes have spots, coffee maker has some scale deposits, or your laundry looks dingy, then your home may probably have a hard water problem.

Though these minerals don’t actually pose health risks, they can make your difficult by creating damaging deposits in your water heater, plumbing, and other appliances that use water like a coffee maker. Hard water can make washing your clothing, dishes, hair, and your body more challenging.

According to the United States Geological Survey, about 85% of American homes have issues with hard water. 

Solving Hard Water Problems

In order to solve the problems of hard water, you have to get rid of the dissolved magnesium and calcium. While there are some chemical treatments that can accomplish this, the best and most popular way is to use a water softener.

A water softener is basically a mechanical appliance that’s installed into the water supply system of your home to filter dissolved minerals from water. 

How Water Softeners Work

Most water softener systems use the same operating concept: They substitute the dissolved minerals for something else, mostly sodium. This process is known as ion exchange.

The main part of a water softener unit is the mineral tank. It is usually filled with tiny polystyrene beads, also referred to as zeolite or resin. These beads usually have a negative charge.

Both magnesium and calcium in water carry positive charges. This implied that these two minerals will get attracted to the resin beads as the water passes through the resin tank. Sodium ions also carry positive charges, which aren’t as strong as calcium and magnesium charges. When a very strong salt (brine) solution is flushed through the mineral tank that has resin already saturated with magnesium and calcium, the volume of the sodium ions is enough to flush the magnesium and calcium ions off the resin. Water softeners come with a separate tank that uses salt to create the brine solution.

When operating normally, hard water usually moves into the resin tank and the magnesium and calcium ions stick on the beads, thus replacing sodium ions. Then the sodium ions enter the water. Once the resin beads get saturated with magnesium and calcium, the unit will enter a 3- phase regenerating cycle. The first phase which is the backwash phase will reverse the water flow in order to flush out dirt from the tank. In the second phase which is the recharge phase, the conc. sodium rich brine solution is carried from the brine tank via the mineral tank. The sodium then collects on the resin beads, thus replacing the magnesium and calcium, which usually go down the drain. Once the recharge phase is over, the ion exchange or mineral tank is flushed to remove excess brine and then the brine tank is refilled.

Types of Water Softeners

By far the commonly used and most popular type of water softener is a cation exchange or ion-exchange unit. However, a couple of other devices with different working mechanism also exist. The following will explain the different types of water softeners on the market today.

1. Salt-Based Ion Exchange Water Softener

This water softener type is very common in many households used two tanks to cycle hard water: one filled with brine solution and the other with special resin beads. It works using the concept of ion exchange, as explained above. This is by softening hard water by trading sodium ions for dissolved minerals in water such as iron calcium, and magnesium.

2. Salt-Free Water Softener

A salt free water softener unit uses ion exchange principle like the salt-based but instead of sodium substitute, it uses potassium chloride. This type of water softener unit might be a better option for folks who want to reduce salt intake. This water softener type is actually a descaler as in it does not reduce the hard water minerals but instead prevents them from being deposited as scales on the surfaces of pipes and water-using appliances. Experts say that using salt-free water softener is better than using no softener at all, although it’s not as effective as conventional water softeners. 

3. Dual-Tank Water Softeners

When a softener is recharging, it first disconnects from the water system, so basically, it’s out of commission. Thus, for this reason, the regeneration cycle is set to happen at night. If soft water is needed when the regeneration cycle is happening, this can be a problem.

If this downtime of a water softener is a problem or if your household is big or you live in a place where water is hard, it may be a good idea to consider investing in a dual-tank water-softener which comes with two mineral tanks. With a dual-tank water softening unit, when one resin tank is in use, the other will be regenerating. Therefore, softened water will be supplied continuously. 

When buying a dual-tank water softening unit, keep in mind the space it’ll require. You need to install it in place it can serve the main water line so that it can supply your entire house. This unit will also need a drain for backwashing. If you opt for a model that needs electrical power, make sure a power outlet is located nearby.

4. Magnetic or Electronic Water Softeners

A more controversial and perhaps cheaper option of softening hard water is a magnetic or electronic water descaler or softener.

According to manufacturers of these units, this plug-in device, which attached to the incoming water pipe, creates a magnetic field which alters the electro-magnetic properties of the hard calcium-carbonate minerals so that they are repelled by each other and by the pipes. Some people say that magnetic water softer works while others say otherwise.

These are the different types of water softeners. Hopefully, this article and water softener reviews by homefixplanet will help you make an informed decision before shopping for one. Make sure you read reviews of them first before making up your mind.