Watertechadvice.com is supported by readers. If you purchase through referral links on our site, we make a commission at no extra cost to you. Learn more.

Home » Reverse Osmosis Systems » Reverse Osmosis vs Water Softener

Reverse Osmosis vs Water Softener

By: Craig Smith
Last Updated:

If you are fighting some water hardness issues because of the presence of minerals and other contaminants in your home’s tap water, you may be deciding whether to go with a water softener or a reverse osmosis filter to clear those problems up.

This is a decision that needs to be looked at closely because these two water enhancement devices are intended to give you very different results.

As a person who has worked around water and ways to filter it almost my entire adult life, I will give you more in-depth information on how water softeners and reverse osmosis filters work and what you can hope to accomplish by using each one of them.

That way, when it comes down to you making a water hardness removal decision based on reverse osmosis vs water softener treatments, you will have the necessary information to make the best choice.

I will thoroughly cover the following in this article:

  • What’s Reverse Osmosis Filtration?
  • What’s Water Softening?
  • The Main Differences Between Reverse Osmosis and Water Softening
  • When Should You Use Water Softening or Reverse Osmosis Filtration?

What’s Reverse Osmosis Filtration?

Reverse Osmosis Systems

Reverse osmosis water treatments are not something that is new. This method for removing impurities and hardness in water has been around since the mid-1700s.

It did not, however, become cost-effective to use until the late-1900s when new types of polymers were used in making the membranes that these types of water filters require to work.

I will try to describe the somewhat complex way that reverse osmosis filters work in Layman’s Terms. It’s basically a water purification method that is intended to better purify water by removing water hardness causing contaminants, solid substances, minerals, and molecules.

These devices do this with a combination of filtration and ionization.

Reverse osmosis filters are designed to increase pressure on the water that comes into them on the supply side of the device. This pressure causes that water to press up against a semipermeable membrane in the center of the device. This membrane allows solvents (in this case water) to pass through it but solutes (solid particles that cause water hardness) cannot.

This results in a water solution that is much purer on the service side of the system as water hardness causing particles are trapped on the supply side of the device.

Reverse osmosis filtration systems use a four-step process to purify tap water. The steps are:

  1. Pre-Filtration – water passes through carbon-based pre-filters to catch sediments and minerals
  2. Reverse Osmosis – here the above described reverse osmosis process takes place
  3. Storage – the purified water passes out of the device and is stored in a small tank for later use
  4. Drainage – the residual supply-side water with contaminants drains out of the system

Reverse osmosis filtration systems typically remove up to 99% of contaminants that are found in home tap water. The most important of which are:

  • Salts
  • Oil and Fat-based Molecules (Colloids)
  • Organic Bacteria
  • Pyrogens (problematic protein-based substances caused by the presence of bacteria)

Other Resources:

What’s Water Softening?


Water that contains a high mineral content is better known as hard water. The most common and problematic minerals found in hard water are calcium and magnesium.

Hard water is known to cause a large variety of problems around your home. This includes:

  • Making your tap water cloudier and taste worse
  • Hard water causes unsightly and hard to clean scale buildup around sinks and faucets
  • Soap scum accumulates more quickly on the shower, tub, and other surfaces that water frequently contacts
  • Hard water causes corrosion on plumbing and can even accumulate to the point where it slows or clogs drains
  • Glasses and dishes get unsightly water spots after cleaning
  • Laundry feels stiff after its washed and whites look very dull or even stained
  • Hair becomes lifeless as it dries out quicker and for many people, hard water causes dryer skin
  • It shortens the usable life of many appliances

So, as you can clearly see, living with hard water conditions is something that becomes very aggravating and problematic over time.

Adding a water softener to your home’s plumbing line will significantly reduce or eliminate a large majority of contaminants that cause hard water problems.

Water softeners work using basic water chemistry. Most hard water contaminants are made up of positively charged molecules.

To attract and eliminate these positively charged contaminants, water softening systems have negatively charged resin beads placed inside them.

So as hard water passes through a water softener, the positively charged contaminants such as magnesium and calcium are captured and pushed out of the system. This leaves only cleaner and softer water to enter your home’s water supply.

This effectively eliminates or significantly reduces all of the above-mentioned problems that are associated with hard water.

The Main Differences Between Reverse Osmosis and Water Softening

Below is a comparison of reverse osmosis vs water softening:

TraitReverse Osmosis FiltrationWater Softeners
EffectivenessRemoves contaminants and chemicalsOnly removes contaminants
Water Use EfficiencyRemoves contaminants and chemicalsWater wasted mostly during the regeneration cycle
Impact on Water PuritySignificantly improves the purity & taste of tap waterMay slightly improve water taste
Ease of MaintenanceFilter needs to only be replaced once every 2-3 yearsNeeds regular maintenance, 6-month filter replacements
Operational CostExpensive if used to treat more than drinking waterCost-effective way to produce large amounts of soft water

When Should You Use Water Softening or Reverse Osmosis Filtration?

If the main goal with your home’s water is just to prevent scale buildup and the related problems that go along with that, then installing a water softener is definitely the way to go.

On the other hand, if you aim to significantly improve the taste and purity of your home’s tap water, then by all means go with reverse osmosis filtration.

I will even suggest that you add each of these water enhancing systems to your home water supply to get the best of both worlds.

When a household water softener is combined with an under-sink reverse osmosis system, you will generate a large amount of soft water inexpensively and get significantly purer and better-tasting water to drink and cook with. 

Enjoy the Benefits Softer Cleaner Water Offers You

The multitude of problems hard water causes in your home are not something that you have to or should want to live with.

Especially since both water softeners and reverse osmosis filtration devices have gotten to the point where they are very affordable for all that you get from them.

So if you have a hard water problem in your home, I urge you to check out some of the best water softeners and RO systems on the market.

Once you experience the difference in your water quality, you will wonder why you did not install a reverse osmosis filter or water softener much sooner.

Photo of author
Craig Smith
Craig got his start in water working in the swimming pool and spa industry. Water treatment would grow into his main career but he ended up working in the pool industry for over 26 years where much of his time was spent balancing the water in customer's swimming pools and installing water filtration equipment. Craig offers an abundance of water treatment knowledge after helping homeowners get pure water for 26 years.

Learn More About The Water Tech Editorial Team