Water Softener Vs Reverse Osmosis (Detailed Comparison)

Water filtration may seem simple, but considering the wide range of options available, it may become a complicated task.

Two of the most common water treatment options include simple water filters and water conditioners; this further makes it difficult for homeowners to decide whether to opt for a reverse osmosis system or simply use a water softener (conditioner).

Water Softener Vs Reverse Osmosis

Thus, you will have to conduct proper research when it comes to water softener vs. reverse osmosis. We understand scrolling through multiple sites can be a nuisance, so our article will provide you with an in-depth comparison of water softener vs. reverse osmosis.

An Insight Into Water Softener & Reverse Osmosis:

A water softener and reverse osmosis are two different modes of water treatment. Water softener merely acts as a conditioner for water, whereas reverse osmosis is the complete removal of contaminations and impurities from your ordinary tap water. Here’s a detailed insight into this.

Water Softener:

Water Softener Vs Reverse Osmosis

In layman’s terms, water softener is a conditioning process to help remove certain minerals (a blend of calcium [Ca]/magnesium [Mg] salts) from your ordinary tap water. The removal of these minerals leads to softening of hard water. The entire process of water softening works on the principle of ion exchange.

It essentially contains a high concentration of dissolved particles like Ca and Mg salts, ranging from 120 to 180 PPM, to characterize hard water. Anything less than this limit is med-hard, whereas higher than this is extremely hard.

Now to remove this hardness, water softeners are used. During the ion exchange process in water softening, the resin (media) in the water softener is introduced with Na (sodium) ions in the tank.

When the Ca and Mg ions interact with the resin, the ions are replaced with Na ions; thus, balancing the concentration of Ca and Mg and resulting in soft water.

Now, when do you need a water softener?

A water softener is different than water filtration systems, and there are specific cases where you need a water softener. One of such cases is when you are using groundwater for your household needs. Groundwater is extracted from tube wells, bore wells, and direct sources of extracting water from the ground.

It is very hard in nature because Ca and Mg (naturally existing in the earth’s crust) are readily soluble in water since water. A water softener will yield the desired results to remove this hardness and make it safe for drinking.

If left untreated, hard water will lead to scaling within your water pipes, water heaters, and radiators. As a result of this scaling, your pipes will be damaged beyond repair if left untreated.

But that’s not all. Other than the safety of your pipes, water softeners can also benefit you in the following ways:

  • Your glassware, silverware, tiles, or anything that you clean with soft water will be significantly cleaner, and shiner.
  • Your hair will also be soft and smooth.
  • Your skin conditions will improve if you bathe with soft water.
  • Your laundry will also be cleaner and brighter.
  • Soft water lowers the use of soap and shampoo up to 75% since it lathers extremely well.

Reverse osmosis:

Water Softener Vs Reverse Osmosis

Reverse osmosis filtration system works by passing water through a membrane with high pressures. It separates contaminations and impurities from your water and passes the clean water through multiple layers of filters.

The reverse osmosis system is connected to a pressure pump that passes water through the filters: the carbon filter, RO membrane, and a post-filter.

The water passed through a reverse osmosis will be free from any contaminations, chemical elements (calcium, magnesium, sodium, nitrates, chlorides, carbonates), bad taste, bad odor, impurities, disease causing bacteria, pathogens.

Reverse osmosis systems are so strong that even the healthy minerals or nutrients in the water are removed. But fortunately, there are certain post filters installed in a reverse osmosis system that re-mineralizes your water.

RO systems are highly efficient and can remove up to 90% of dissolved particles by forcing water through multi-layer filters. It is considered one of the most effective purification systems of water.

Not only does an RO system provide you with better value for money during your initial purchase, but it also requires lesser maintenance and energy for operation. Here are some benefits of an RO system.

  • Removes 90% of the overall dissolved particulate matter
  • Completely wipes away heavy metals from your water
  • Pesticides, pathogens and other organic compounds are also removed
  • Significantly improves the quality of water
  • Provides a constant supply of safe water
  • Easy to operate and maintain

Do You Need A Water Softener With Reverse Osmosis?

Water processed through a water softener is soft, and most of the hardness is removed, thus, making it ideal for household tasks and other purposes except for direct consumption. This is because a water softener only removes the hardness of your water by lowering the Ca and Mg composition of water.

Whereas the rest of the total dissolved solids (TDS) are still in high concentration. So, a reverse osmosis system will help you remove the TDS from your water. Now, when it comes to using a softener with reverse osmosis, it will be a great option.

The answer to the initial question is yes! You do need a water softener with a reverse osmosis system. Here’s why.

When a water softener is combined with a reverse osmosis system, it will greatly benefit you in terms of providing you with a constant supply of clean water throughout your household. In addition, it will also lower the frequency of wear and tear on the filters in your RO system.

So, ultimately, the life of your RO system will increase significantly compared to using an RO system exclusively without a water softener.

Does Reverse Osmosis Remove Salt From Water Softener?

If you, like most people, are concerned about the amount of salt in your water, you may wonder if reverse osmosis will remove salt from the water softener.

As you might already know, water softeners rely on sodium to be replaced with Mg and Ca ions during the ion exchange process and essentially flushes them out, resulting in soft water.

The soft water will still contain sodium ions in very small amounts. It will not give your water a salty taste, and you strictly do not have to worry about getting a salt dose from your water every time you drink a glass of water.

But, if you’re health conscious, you’re in luck! Reverse osmosis systems can help you remove the excess salt from your water softener! When you pass a softened water source from your RO system, it will effectively remove the Na ions and remove any taste or smell your water may have.

Does Reverse Osmosis Remove Sodium From Water Softener?

Water Softener Vs Reverse Osmosis

When sodium from the water softener is passed through a reverse osmosis system, it will be removed by the multi-layered filters of a reverse osmosis system. Over 90% of impurities, including the sodium content from a water softener, are filtered out using an RO system.

So, in simple words, Yes! Reverse osmosis removes sodium from a water softener, ensuring a safe and clean water supply throughout your household.

Does Reverse Osmosis Eliminate The Need For A Water Softener?

The answer to this question depends on the type of filtration your water needs.

If your water is hard and filled with impurities (unprocessed water), a reverse osmosis system will provide you with clean and safe water (softened as well). But unfortunately, a lot of water is wasted when filtered through a reverse osmosis system.

Whereas, if your water is already filtered and simply hard, a water softener will be your most beneficial option.

Based on this, we can conclude that reverse osmosis can eliminate the need for a water softener if you have both a contamination and hardness problem. If you have a hardness problem and your water is already filtered, you will have to use a water softener instead.

Does Reverse Osmosis Go Before Or After A Water Softener?

Technically speaking, a reverse osmosis system should go after a water softener. A water softener greatly reduces the Ca and Mg ions in untreated water and replaces them with Na ions. This significantly lowers the hardness of your water and turns it into softened water.

Now, when a water softener is attached before a reverse osmosis system, the output of the water softener (softened water) will be the RO system’s input (source) water. As a result, it will have lesser wear and tear on the filters in your reverse osmosis system.

This will greatly improve the life of your RO system, so based on this, your RO system should go after a water softener.

Does Reverse Osmosis Make Water Soft?

Yes, reverse osmosis can efficiently remove hardness from your water and makes it soft. However, many homeowners prefer installing a water softener at the source before the water is filtered through a reverse osmosis system.

The primary reason behind this is that it reduces the overall maintenance and operating costs of using a reverse osmosis system. In addition, it also results in lesser wastewater produced.

How Does A Reverse Osmosis Water Softener Work?

A reverse osmosis water softener works by passing water through multiple layers of semi-permeable membranes.

A reverse osmosis water softener comprises the following parts:

  • Sediment pre-filter
  • Activated carbon pre-filter
  • Reverse osmosis membrane
  • Post-filter (for re-mineralizing)

Water is passed through these filters using a pressure pump, reducing almost all of the contaminations and impurities and removing the chemical compounds from your water (including minerals). All these filters collectively produce clean water, which is not only soft but also free from any taste, odor, and harmful impurities.

Will Water Softener Damage Reverse Osmosis?

No, water softeners will not damage reverse osmosis systems. In fact, it is the other way around. Water softeners provide your reverse osmosis systems with pre-treated water with a significantly lesser concentration of Ca and Mg ions.

As a result of the lesser Ca and Mg ions, it will lower the amount of wear and tear on your reverse osmosis system. Thus, ultimately it will result in an increased life of your RO system.

Conclusion: Which Is Better Reverse Osmosis Or Water Softener?

To conclude, reverse osmosis and water softeners both serve different purposes. A water softener simply conditions your water by removing Ca and Mg ions and replacing them with safer Na ions, thus giving you soft water.

Whereas reverse osmosis is the complete package and removes all of the contaminations and lowers the hardness of your water. To answer the question of which one is better amongst the two, it comes down to your requirements.

If your water is simply hard and has no contamination, a water softener is the better choice. Whereas if your water is hard and contains contaminations and other taste/odor-altering compounds, a reverse osmosis system will be the better option.


This is my blog about the ways and solutions that can help you improve your health by taking more value from drinking water. As improving health means a lot to me, I decided to create the Water On Top project with the purpose to reveal the benefits of water, the finest products to take our daily water to another level, and much more great stuff about water that I believe is on top of our nutrition.

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