How a Water Softener Works - The Science Behind Getting Soft Water
Many people have a water softener in their home. Water softeners turn "hard" water into "soft" water. Even though water softeners are popular home additions, most people aren't really sure how they work! In this article, we'll show you the science behind how a water softener works, and why they're beneficial for you and your family. Contact us today at Watersmart if you want to learn more about the benefits of water softeners.
How Does A Water Softener Work?
The Parts Of A Water Softener
If you don't have a water softener, you may be wondering what kind of machinery is capable of transforming water from hard to soft!
In order to understand how water softeners work, it's important to know a bit about their parts.
A water softener is essentially a large filter. Water softeners have three main parts: the mineral tank (where hard water is turned into soft water), the brine tank (a tank that contains water that is saturated with salt, or "brine"), and the control valve (control center for your tank that determines when "resin bead" cleaning is necessary).
Image source: Priority Response Plumbing
The Science Behind Water Softeners - Hard VS Soft Water
Image source: Benbell Softener Systems
Water softeners help turn hard water into soft water. But what exactly is "hard" or "soft" water? Hard water is simply water that contains "an appreciable amount" of dissolved salts and other minerals. The minerals most commonly found are magnesium and calcium.
Soft water is water that contains significantly less dissolved salt and minerals. In order for water to be deemed "soft," it must have a mineral content of less than 17.1 mg/l.
Rainwater is naturally soft water. It becomes "hard" after it picks up minerals from the ground. A water softener helps convert water back to its original form, as it was before it interacted with all those minerals in the ground.
Water softeners use chemistry to accomplish this, and a system called "ion exchange." Though this process may sound confusing, we have broken it down into parts below.
Understanding Ion Exchange
What is ion exchange? First, let's explain what ions are. Ions are "atoms or molecules containing a total number of electrons that are not equal to the total number of protons" (source).
Ion exchange is when unwanted ions, such as magnesium and calcium ions (positive charges), are replaced with wanted ions, such as sodium or potassium ions (negative charges).
When hard water enters the water softener's mineral tank, it comes into contact with resin beads. Resin beads are small beads coated with salt ions. As water flows through the mineral tank, ion exchange takes place.
The positively charged magnesium and calcium ions cling to the negatively charged resin beads, thus removing them from the water. The unwanted "hardness ions" (magnesium and calcium ions) are replaced with the "softness" ions (sodium or potassium ions).
Do Resin Beads Work Forever?
Resin Beads - photo by Adam Smith
No, they do not. Ion exchange, as the name suggests, is the exchanging of ions. That means the hardness ions from magnesium and calcium are exchanged with the softness ions on the resin beads. Eventually, the resin beads contain only hardness ions, as they have exchanged all of their softness ions.
However, that does not mean your water softener no longer works! As mentioned above, with most water softeners, the control valve determines when your resin beads need to be recharged. When your resin beads are coated with hardness ions, all you need to do is add water softener salt to your brine tank.
Once you add salt, the ion exchange process happens again, this time in reverse! The hardness ions on your resin beads are exchanged with the softness ions in the salt water. Then, the excess minerals wash away into the wastewater drain (source).
Sodium In Soft Water
Now that you know how the water softener process works, you may be wondering what happens to all that salt in your soft water. When using a water softener, there will be some amount of sodium (salt) leftover in your water.
Though this salt is unlikely to become noticed, some homeowners do complain of a "salty" taste in their water. Aside from the taste,the salt doesn't pose a health risk. However, for those on a sodium-restricted diet, it can be cause for concern.
If you cannot stand the salty taste or cannot have salt in your diet, you have the option of installing a separate water dispenser that actually has the ability to bypass the water softener. Another option is to use a different chemical. Potassium Chloride works the same way as salt does, but is more expensive (source).
Water Softeners And Other Minerals
Have you ever noticed a rotten egg smell in your sink after running your tap water? What about annoying rust stains that just won't seem to disappear? The rotten egg smell is actually caused by hydrogen sulfide gas. Those rust stains or other staining you notice can be caused by ferrous iron or manganese.
Hydrogen sulfide gas, ferrous iron, manganese, and other minerals can also be found in your tap water. However, water softeners cannot filter these impurities out of your water. If you suspect your water problem is not magnesium or calcium causing hard water, you will need a specialized water treatment system equipped to deal with those minerals (source).
If you aren't sure if you may benefit from a water softener, don't hesitate to talk to an expert and find out!
Other Questions About Hard & Soft Water
How Do I Know If I Have Hard Water?
You can measure if your water is hard or soft by testing the pH levels of your water. pH measures how acidic or alkaline any given solution is. You can also test for hard water by measuring using the parts per million (ppm) scale. A higher number on the ppm scale indicates harder water.
Your Health: Should I Be Worried About Hard Water?
As we learned above, rainwater is naturally soft water. It does not turn into hard water until it comes into contact with the ground and picks up minerals, any soluble bits, and other possible contaminants. Though water can get contaminated, most of the time, the minerals and soluble pieces that rainwater picks up are not actually harmful to consume.
hard water mostly contains magnesium and calcium. These two minerals, although they will not hurt you if you drink them, can make household chores more difficult. Both magnesium and calcium interact with common household items, such as soap, and impact their ability to work as intended.
For example, when washing your hair with hard water, your shampoo and soaps will not dissolve completely. Soaps interact with magnesium and calcium in the water, coagulating with the soap, and thus your soap loses its effectiveness. The coagulated soap and shampoo become harder to rinse off. It is also more difficult to fully rinse out hair, which may become dull over time (source).
Hard water can also leave annoying water spots on any object you may have washed. This is most noticeable on plates and dishware. Your pipes may also suffer from hard water, as calcium slowly builds up and begins blocking water flow (source).
Though hard water will not hurt you, over time, it can become a nuisance, reduce your ability to clean your home (and yourself), and even damage pipes and appliances.
Interested In Your Own Water Softener?
"Purchased a water softener, price was reasonable, sales staff was very informative and not pushy. Install was quick and clean and he gave instructions on the unit. I would highly recommend Watersmart Systems."
- Rob, More testimonials here!
Now that you know exactly how water softeners work, you may be interested in your own! Or you may have realized that your water softener is not working as it should. Water softeners, for the most part, are very reliable and require minimal or no maintenance to keep them running.
However, at your request, we can check for salt bridging, inspect water flow, adjust regeneration frequencies, conduct water testing, sanitize the tank, and more. If you would like us to perform an inspection or preventative maintenance check, give us a call and we would be happy to discuss further.
Where Are We Located?
Our office is conveniently located at 105 Lexington Road, Waterloo, ON. Give us a call today to learn what we can do for your water.
To get directions, click here.
watersoftenerfacts.ca / thespruce.com / fluencecorp.com / popularmechanics.com