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Home » Reverse Osmosis Systems » Is Reverse Osmosis Water Bad For You?

Is Reverse Osmosis Water Bad For You?

By: David Trinh
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Reverse osmosis is a common method of water filtration that can be used in your home. Instead of having a filter attached to your faucet, this system is installed under your kitchen sink. That way, when you turn on your faucet you’re getting fresh filtered water.

It sounds like a simple solution, but the World Health Organization (WHO) has released information showing the potential risks of demineralized water (or RO water).

When that type of information comes from a well-established government organization, it’s understandable that people react with caution. There are advantages and disadvantages to drinking reverse osmosis water, so you need to be informed.

At the end of the day, reverse osmosis water is not bad for you. If you’re looking for an RO system, check out

But, we will let you decide based on our research. So, let’s first learn all about the process of reverse osmosis, what it does, and what type of water it produces.

What Is Reverse Osmosis Water?

Reverse osmosis water has been filtered using the process of reverse osmosis. This system uses several different filters to ensure all contaminants are removed from the water before you use it for drinking, cooking, bathing, and other chores around your home.

Osmosis is a process when diluted solutions passively flow through semipermeable membranes into more concentrated solutions. For example, plant roots use osmosis when they pull water up from the soil.

Reverse osmosis is the opposite of this process. You start with a highly concentrated solution, like saltwater, and use filters to make it a lower concentrated solution. Instead of being passive, it requires pressure to push water through filters to eliminate impurities.

First, a sediment pre-filter extracts large particles and pushes the water through to the next filter, which is an activated carbon filter. These filters remove gases and chemicals from the water. Lastly, the water flows through a semipermeable membrane which catches smaller particles as the water flows through the post-filter and out of the faucet.

The pores in the filters are so small that only water molecules can fit through. To give you an idea of how small, feel a strand of your hair. Your hair is about 100 microns wide. A pore in a reverse osmosis filter is about one micron wide.

The water you’re left with is the freshwater solution. Contaminants that are removed from the water are held back in the reverse osmosis chamber in a solution called brine. The brine flows down the drain with other water waste.

What Does Reverse Osmosis Remove From Water?

removes over 99

Reverse osmosis is a very effective method of filtration, removing 90 to 99% of contaminants from the water. These impurities include:

You don’t want these contaminants in your body, so it’s reassuring that your system can keep them from your drinking water. However, reverse osmosis works so well to purify that it strips many healthy minerals from water, like:

  • iron
  • zinc
  • copper
  • iodine
  • calcium
  • phosphorus
  • magnesium
  • fluoride
  • potassium

Iron helps your body transport oxygen. An iron deficiency results in anemia, decreased immunity, and impaired motor development. Zinc is necessary for growth and development. Copper strengthens bones and promotes red and white blood cell maturation. A lack of iodine can lead to thyroid problems.

Calcium is crucial for bone health and is the most abundant mineral found in human bodies. Phosphorus also relates to bone density and muscle weakness. Magnesium deficiency can lead to cardiovascular disease, type 2 diabetes, and hypertension.

Fluoride naturally strengthens enamel, prevents tooth decay, and protects against cavities. You can buy toothpaste with fluoride added, but this will only apply it to the surface of your teeth. Potassium lowers your blood pressure and prevents strokes.

Fortunately, you don’t depend on your drinking water for these elements. You can get these minerals from food and supplements so even if reverse osmosis removes them you should be fine if you are eating a healthy diet.

Advantages of Reverse Osmosis

Advantages of Reverse Osmosis

Reverse osmosis is a method that has many benefits, especially when you consider your health.

1. Don’t Have to Worry About Contaminants

Drinking purified water means you won’t have to worry about bacteria and viruses in your water. Herbicides and pesticides can be found in a municipality’s drinking water due to crop runoff, so filtering your water will eliminate those contaminants.

2. Clean Easy Access to Water

Filtering your water at home will keep you from having to buy purified bottled water from stores. This saves you money and is also more environmentally friendly. You can refill reusable bottles from your kitchen sink and drink filtered water.

3. Clean Water for Cooking

RO water is also good for cooking. Unfiltered water might have minerals like sulfur or chlorine that affect the taste of your food. Using filtered water to boil food or use it as a baking ingredient will ensure your food tastes naturally come through.

4. Removes Hard Water Causing Minerals

If you have hard water at your house, then you might have a softening system installed. While it’s better to use this method than to deal with hard water, there are some adverse effects. You’ll have more sodium in your water once it’s softened, but reverse osmosis will remove this mineral. So using an RO filter and softener will ensure you have pure water without excess sodium or hardness causing minerals.

5. One of The Most Effective Filtration Methods

The Environmental Working Group has rated reverse osmosis as the most effective filtration system in terms of removing contaminants, so you know you’re getting a method that’s tried and true.

Disadvantages of Reverse Osmosis

Disadvantages of Reverse Osmosis

While there are many benefits to using reverse osmosis water, it’s only fair to address the disadvantages as well.

1. RO Units Can Be Expensive

Installing a point-of-entry reverse osmosis system at each of your sinks can be expensive. You also have to be diligent with your maintenance because a torn filter could cause contaminants to leak into your drinking water as well as additional repair costs.

2. Need to Change Filters

Filters have to be changed every 6 to 12 months, and the semipermeable membrane must be replaced every 2 years. These routine costs can add up over time. You might find it’s worth doing the math to figure out how much you spend on bottled water and see how much you’ll be saving in terms of reverse osmosis installation and maintenance.

3. RO Creates Waste Water

Even though the filters and membranes are designed to push water through, there will still be water that is wasted in this process. Because the contaminants stay in part of the machine as the filtered water flows through, you will have to wash them back down the drain with water.

4. RO Removes Healthy Minerals

Since minerals are being removed, you’ll find that reverse osmosis water will taste different than regular tap water. Some consumers describe it as tasting “flat” and find it unappealing. You might not drink as much water as you should if you find the taste off-putting, so you’re at risk of becoming dehydrated.

Lastly, don’t forget the fact the WHO brought to consumers’ attention: reverse osmosis removes all minerals from the water if it doesn’t contain remineralization.

Check Out: Best Reverse Osmosis Systems With Remineralization

It’s reassuring that the process works so well, but since some of these minerals can benefit your health, doesn’t that make it worse to remove them?

Yes and no. Remember, if you are eating a healthy diet you should be getting all these minerals anyway in the form of food so it’s not a huge concern. At the same time, it is healthy to get some minerals from your water supply so the decision is really up to you.

There’s also a way to remineralize reverse osmosis water if you want to get the best of both worlds so look for an RO filter that also contains remineralization.

Remineralizing Reverse Osmosis Water

Since reverse osmosis removes over 99.9% of total dissolved solids from the water before it leaves your faucet, you might want to remineralize it with the healthy minerals you’re missing.

Remineralizing your reverse osmosis water will help give back some of the classic water taste you enjoy. Taking this step to make your water taste better will help ensure you’re drinking enough water every day to stay hydrated and healthy.

You can buy a reverse osmosis system that comes with a remineralization filter. This filter is installed after the post-filter, so the reverse osmosis process does all of the work to remove contaminants. Once the water is purified, it will run through the remineralization filter where the healthy minerals are reintroduced to the water.

If your system didn’t come with a remineralization filter, you can buy one and install it right after your reverse osmosis system ends.

Also, many health stores sell mineral drops. You can buy bottles that contain copper, iodine, iron, zinc, magnesium, and more. They aren’t too expensive and are low in sodium so you don’t have to worry about adding the wrong thing back into your water.

The drops you buy will have specific instructions, but typically they’re so concentrated you just add a few drops per pitcher of water. These drops add minerals back into the water for your health, and also improve the taste just as a remineralization filter would do.

Keep in mind that it’s totally fine to drink reverse osmosis water without remineralizing it. These options are for consumers who want to get all of the possible health benefits directly from the water without relying on just food for minerals.

Alternatives to Reverse Osmosis

Reverse osmosis isn’t the only filtration option if you want to purify your water at home. There are other filters and processes you can use to get slightly different results.



Distillation is a filtration process that is more affordable than reverse osmosis and doesn’t require as much maintenance. This method uses evaporation to boil water into steam. The contaminants don’t have the same boiling point as water, so they remain in the pot as a liquid.

The boiling process kills off bacteria and viruses. The steam condenses back into water in a separate section of the container. The resulting water is just as pure as what you get from reverse osmosis, but the process takes much longer. Distilling one gallon of water can take up to four hours to produce.

The distilled water system itself can be installed under your sink or on your countertop. The size of the distiller will impact how much water it produces each day. You should store the extra distilled water in a glass pitcher because it will leach minerals from plastic containers.

Carbon Filtration


Carbon filtration is an ideal alternative to reverse osmosis if your municipality’s water is of decent quality. This method isn’t as thorough as reverse osmosis, so it doesn’t eliminate all of the trace minerals, especially fluoride.

Carbon filtration is one of the most effective forms of eliminating major contaminants like lead and chlorine from your water. The activated charcoal in the filter adsorbs, or traps, harmful chemicals while allowing water to pass through.

Carbon filtration systems are available as whole-house and portable solutions. You can install them at your water line so filtration happens before the water comes out of your sinks. You can install small filters directly onto each faucet. You can even buy pitchers that have carbon filters in them so you can keep water cold in the refrigerator and filter it as you pour.


Ultrafiltration uses high pressure to push water through a semipermeable membrane, just like reverse osmosis. This works to remove large particles from the water as it purifies. However, since the filters have bigger pores, smaller contaminants like bacteria and viruses can still slip through and remain in your water.

KDF Filtration

Kinetic degradation fluxion (KDF) filtration uses granules of copper and zinc to oxidate chemicals from your water. The process renders the chemicals harmless so they are washed out of the system without contaminating other water sources.

While it’s not as thorough as reverse osmosis, KDF filtration is most effective at eliminating metals. If you want to further purify your water, you can combine this method with carbon filtration.

Is Reverse Osmosis Water Bad For You?

The final verdict is in: Reverse osmosis water is not bad for you.

It might seem like a bad thing to drink water that doesn’t contain healthy minerals, but as long as you’re getting these from other sources, drinking reverse osmosis water is perfectly fine.

This type of water is a healthy choice if you’re concerned about contaminants in your municipality’s water supply. Any harmful chemicals and excessive minerals are filtered out so you’re consuming pure water. As long as you’re staying hydrated, reverse osmosis water is fine to drink.

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David Trinh
David is an expert in all things plumbing, heating, cooling, and water treatment. He got his start in the plumbing business working on fixing all types of home improvement issues including water leaks, broken toilets, appliance installation, and more. Over time, he learned a ton about installing and choosing the correct water treatment products for homeowners.

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