Water Treatment FAQ: Reverse Osmosis vs. Water Softener

When it comes to your home’s water, there are plenty of potential quality issues to look for — but the good news is that there are a broad variety of treatment solutions. The only thing you have to do is find out which is the best one for your needs.

For example, you’ve likely heard about reverse osmosis (RO) and water softening. They’re both water treatment methods, but they’re separate processes. The main difference is that reverse osmosis focuses on drinking water quality, addressing a variety of contaminants that could cause taste, odor and health concerns, while softening removes the excess calcium and magnesium that cause hard water.

That means it’s important to know when you need reverse osmosis, when you need softening and when these solutions can work together. Here’s how to find out.

What Is Reverse Osmosis?

In reverse osmosis the filtration system forces water through a semipermeable membrane. This RO membrane acts like a net, catching a wide variety of impurities — including particles so small that you can’t see them.*

A reverse osmosis system often combines multiple methods into one comprehensive treatment solution. That means in addition to the RO process,  you get additional filtration stages all working together to address water quality issues such as:

• Total dissolved solids (TDS)
• Chlorine
• Viruses
• Bacteria
• Nitrate
• Copper
• Lead
• Microplastics
• And more

What Is Water Softening?

Water softening removes the excess calcium and magnesium that cause hard water. Hard water, which is broadly common across North America, causes a mineral buildup that can lead to spots on dishes and shower doors; dry, dull hair and skin; stiff, faded laundry; and even lower efficiency or breakdown of water-using appliances.

Here’s how water softening works, using a process called ion exchange: Your water flows through a tank containing tiny resin beads, which are negatively charged. The positively charged calcium and magnesium ions are attracted like magnets and trapped on the resin beads while the rest of the water flows through freely.

Your water softener also includes a second tank called a brine tank. This is filled with a salt solution that rinses the mineral ions off the resin so it can continue to work effectively. Some water softeners do this at regular intervals or based on how much water has flowed through the system. For maximum efficiency, the best water softeners use technology to monitor the condition of the resin and only regenerate as needed.

Although softening is a type of water treatment, it isn’t the same as filtration. Similarly, while some water filtration systems may target minerals, they use different processes and aren’t considered softening solutions.

Explore water softening systems for your home.

Reverse Osmosis vs. Water Softening

Now that you know the basics, it’s time to compare RO and softening based on a few key characteristics. Here’s a closer look:

Processes

One of the main differences between reverse osmosis and water softening is the method used to achieve the desired result. RO works almost like a net to “catch” and filter out contaminants, while the latter works more like a magnet to attract and trap hardness minerals. Similarly, RO uses a semipermeable membrane while softening uses resin beads.

Another important difference is that reverse osmosis doesn’t have a regeneration phase. Unlike the resin beads in a softener, an RO membrane doesn’t require frequent rinsing; instead, an annual system sanitization is recommended,  along with replacement of the RO membrane as needed — and the best membranes can last up to five years.

Target Areas and Results

The most important difference between reverse osmosis and water softening is what they actually do.

RO is all about addressing impurities. This can include noticeable contaminants like chlorine with its swimming pool odor or iron with its metallic taste, but it also targets potentially harmful substances you might not even know about — such as lead and forever chemicals. 

That means reverse osmosis has two kinds of results. First, it helps address the health risks that could come with certain contaminants (and also allows you to skip the plastic waste of single-use bottled water). Second, it fixes aesthetic water issues such as unpleasant tastes and odors.

Meanwhile, softening specifically focuses on alleviating the pain points of hard water, targeting the excess calcium and magnesium that cause it. When you remove these components from your water supply, the resulting soft water helps prevent buildup that could corrode your pipes, damage water-using appliances, stick to your bathroom fixtures and even make your hair dry out.

Costs

The cost of a reverse osmosis filtration system depends on several factors, including the number of filtration stages, third-party certifications, smart features and overall design.

One of the factors in determining the cost of a water softener system is its capacity. That’s because the harder your water, the harder the system has to work to complete the softening process. Other factors impacting cost include available features, how efficiently the system operates, and whether any other types of filtration – such as for common issues like chlorine or iron – are included.

Features

For Culligan, there’s one important similarity between these two types of solutions: our reverse osmosis systems and water softeners both have optional smart features, meaning they can be connected to Wi-Fi so you can track and control settings and performance right from the Culligan Connect app on your phone.

Water Treatment Solutions: Softening Plus Filtration

While it’s good to know that a water filter isn’t the same thing as a water softener, the reality is that these two solutions are better together. Although they treat separate issues, softening and filtration are complementary tools.

That’s because they each focus on different but common water problems. RO might be just the fix for an odd taste in your drinking glass, but it won’t help get rid of the water spots that make that glass look dirty — and that’s where softening comes in. Meanwhile, although soft water is great for healthier-looking hair and nails, it won’t help you avoid the potential risks of water contaminants.

The key to getting the most out of these two solutions is twofold:

1. Find out what you need each system to do.
2. Choose systems that complement each other.

To do this, you’ll need to start with a water test. You’ll learn what’s in your tap water, from contaminants to hardness levels. Your local water expert will help you interpret the results and provide personalized recommendations for systems that best address the identified issues. You’ll also get the chance to think about how these treatment methods work together, what the outcomes will be, and which features are most complementary.

The good news is that there’s no perfect way to do any of this. It’s all about what works best for your home’s water quality — and as soon as you have all the facts, you can confidently make informed decisions based on your own needs.

Soften and Filter Your Home’s Tap Water

There’s no need to choose between softening and filtration. If you want the best results, let these treatment solutions team up to address a wider variety of water problems — from tastes, odors and health concerns to water spots and mineral buildup.

Remember, it all begins with your free, in-home water test and consultation. Schedule yours today.

*Contaminants may not be present in your water.