How does a water softener work to improve the water quality in your home? If you’ve ever considered investing in your own water softener, this may be one of the questions you’ve asked yourself. Water softeners can be valuable tools for homeowners who want to protect their plumbing, enhance their water supply, and reduce the common issues associated with hard water.
While there are different styles of water softening systems available on the market today, most of these tools have similar functionality. They work to soften water by removing excess calcium and magnesium deposits from your supply.
Here’s everything you need to know about how water softeners work.
What Is a Water Softener?
The first step in understanding the water softening process is knowing what a water softener actually is. Essentially, a water softener is a whole-house system for water filtration. It removes magnesium and calcium ions from your water through a process known as “ion exchange”.
Water softeners address one of the most common water-based problems homeowners face: hard water. While hard water isn’t necessarily a health risk, it can wreak havoc on your hair, skin, and home. When your water supply is too hard, minerals build up within your pipes, influencing the taste of your drinking water and shortening the lifespan of water appliances.
Minerals’ hardness in your water can also impact your laundry. If you live in a hard water area, you may need more washing cycles than usual to remove stains from your clothing. When you soften water with a built-in system, you reduce water hardness and limescale buildup. You can also improve the efficiency of your laundry detergent and reduce the amount of soap scum in your home.
What Does a Water Softener Do?
As mentioned above, a water softener removes calcium, magnesium, and other mineral ions from your water through the “ion exchange” process. Most water softeners have two tanks: a brine tank and a mineral or resin tank. The latter includes a series of small resin beads charged with sodium ions. These have a positive charge, which reacts with the charge of magnesium and calcium ions.
The positive charge of the resin attracts the minerals, holding them in place as your water moves through the system. The softened water can then flow freely throughout your home, into your shower, taps, and washing machines.
Water softeners address issues like:
- Damaged washing machines and dishwashers
- Stains on your tubs and showers
- Spotting on glassware and dishes
- High energy bills caused by water inefficiency
- Dry skin and brittle hair
How Does a Water Softener Work?
Because water softeners include a resin bed charged with sodium ions, many people assume the “salt” components in sodium soften the water. However, what actually softens the water is the ability of the resin bed to attract existing mineral ions out of your water. Here’s a quick rundown of how a water-softening process works:
- Hard water enters the home through a pipe or well, travelling to the water softener system.
- The beads in the resin tank attract and hold onto hard water deposits.
- The minerals remain with the plastic beads while the softened water flows into your plumbing system.
Notably, most water softeners have a maximum capacity, so they can only hold so much water at any time. This is why it’s important to consider your water usage and the hardness of your incoming water when choosing a water softener system.
What Are the Components of a Water Softener?
Water softeners are typically made up of three core components: a brine tank, a mineral tank, and a control valve. These components work in conjunction to remove minerals during the softening cycle before sending water to your coffee makers, showers, and kitchen sink.
The Mineral Tank: The mineral tank is the chamber where hard water is softened through the use of resin beads. The water seeps through the beads, depositing the calcium and magnesium ions before it flows into your pipes.
The Control Valve: The control valve tracks the amount of water entering the mineral valve. Over time, the resin beads in your mineral tank exchange sodium ions with hardness ions. Eventually, you must top up your sodium levels to soften water continuously. This will require you to use the control valve.
The Brine Tank: The brine tank helps the water softening system with the process of “regeneration”. This tank sits adjacent to the mineral tank and holds a highly concentrated solution of salt or potassium chloride to restore the positive charge of the resin beads. Salt needs to be manually added to the brine tank in the form of blocks and pellets when the control valve shows the capacity of the resin is diminishing.
What Is the Ion Exchange?
Ion exchange is one of the key processes involved in creating softened water. The resin inside a water softener is made up of small beads with microscopic dimples. These beads feature positively charged sodium ions, which help to attract calcium and magnesium.
The ion exchange process happens when the hard water in your supply runs over the resin beads, and the calcium and magnesium elements are removed. When hard water runs through your mineral tank, the stronger charged ions in calcium and magnesium are attracted to the resin beads, forcing off the other sodium ions.
The hard minerals remain stuck to the resin when the sodium ions are removed from the tank. Because these are captured by the resin, the water supplied from the water tank is then much softer.
What Does a Water Softener Remove?
A water softener creates soft water and improves your water flow by removing magnesium and calcium ions from your hard water. Calcium and magnesium ions are two of the main substances in hard water. The ion exchange process initiated by the resin beads in a water softener can also remove other ions from your water flow, such as iron and manganese.
Notably, most water softeners won’t remove iron and other substances. However, they can assist in removing dissolved iron in low quantities. Dissolved or ferrous iron can often cause stains on sinks and bathtubs.
However, ferric iron is harder to remove with positively charged sodium ions in a water softener. Ferric iron tends to accumulate on the bed of resin beads, which can make the ion exchange process less efficient. That is why specific chemical solutions may be necessary to preserve your soft water.
What Is Water Softener Regeneration?
A core component of the water softener cycle is the “regeneration” cycle. This is when the water softener system inundates the resin beads in the main tank with the highly concentrated solution in the brine tank. The process washes away the hard minerals and recharges the beads once again.
The resin beads themselves are highly durable and can often soften water for years at a time. However, they do need to be “regenerated” regularly. Users can access two forms of regeneration cycle within their water softener.
A co-current regeneration cycle happens when the brine solution flows into the mineral tank in the same direction as the service flow. The magnesium and calcium ions are released as the brine flows over the beads. The solution’s strength is significantly reduced when the brine water exits the tank. Co-current regeneration uses more water and salt than the counter-current cycle.
In the counter-current cycle, water enters the tank through the bottom of the mineral tank, where softened water would usually exit. The cycle runs the brine up the resin bed, beginning at the bottom, where the beads are often the least depleted. This means there aren’t as many hard minerals or ions involved in the re-exchange process. The brine content is then not as depleted by the time it gets to the top of the resin bed. Counter-current cycling water typically uses less salt and water than co-current cycling. It can also distribute recharging sodium ions more efficiently.
Is Soft Water Safe to Drink?
Because water softener systems use a brine solution and sodium ions for ion exchange, some people worry the resulting soft water might not be safe to drink. High amounts of sodium found in a brine solution might be dangerous to consume. However, during the ion exchange process, the amount of sodium released into the softened water is much lower than you might expect.
If you have moderately hard water, with about five grains per gallon, you’ll only end up with approximately 37mg of sodium ions per quart of water. This is less than 2% of the standard daily sodium intake.
The amount of sodium added to your water supply is related to the reduced number of hard minerals. Every milligram of calcium and magnesium in your water releases 2 milligrams of sodium. This only becomes a problem in the ion exchange process if you live in an area with extremely hard water.
Do You Need a Water Softener?
A water softener could be a valuable tool for people who want to remove calcium and magnesium buildup from within their water system. Though you might be exposed to more sodium, the amount introduced to your plumbing system should be minimal.
Additionally, each softening cycle should help reduce energy bills and preserve your plumbing systems. Just remember that if you want to maintain a stable operation, you’ll need to ensure your water softener is installed correctly and completes the regeneration process regularly.