Reverse Osmosis Systems: Myth or Reality? 6 Misconceptions Explained

Misconceptions about reverse osmosis systems: true or false?

Many people think owning a reverse osmosis system can be complicated, that it costs too much, or that it “wastes” too much water.

These are questions we regularly receive and answer. That is why we decided to write an article about them.

The video that debunks misconceptions about reverse osmosis systems

In this short video, we revisit the main misconceptions about reverse osmosis systems

Table of contents
•	Misconception No. 1: “A reverse osmosis system wastes too much water”
•	Misconception No. 2: “It removes all the minerals”
•	Misconception No. 3: “Tap water is thoroughly monitored”
•	Misconception No. 4: “It takes up too much space”
•	Misconception No. 5: “It costs too much”
•	Misconception No. 6: “It is complicated to install”
•	FAQ – Reverse osmosis systems and misconceptions

Misconception No. 1: “A reverse osmosis system wastes too much water”

False.

Older models could discharge several liters for every 1 liter of filtered water.

Today, a household model discharges an average of 1 liter to produce 1 liter. And the newest or most efficient models can discharge less than 0.5 liter of wastewater per liter produced.

For comparison, producing bottled water also requires water, energy, and transportation. If your goal is to reduce your environmental impact (and your purchases), reverse osmosis is a sensible option.

Key takeaway: Modern reverse osmosis systems use far less water than you might imagine, especially compared with drinking bottled water every day.

Misconception No. 2: “A reverse osmosis system removes all the minerals, which is bad for you”

False (and often exaggerated).

Based on what we know today, minerals supplied by water account for a limited share of your intake: water is generally estimated to contribute about 5 to 20 % of your daily intake, with the rest coming mainly from food.

Also, a reverse osmosis system does not remove “absolutely everything”: traces of minerals can remain, and if you want to adjust the taste or mineral content, a remineralization filter cartridge can do that.

A useful reference point: Essential minerals come primarily from food. Water plays a role, but rarely the main one.

Misconception No. 3: “Tap water is thoroughly monitored, so a reverse osmosis system is unnecessary”

Yes, tap water is monitored… but not for everything, and not in the same way everywhere.

There is growing discussion of micropollutants: PFAS, pesticides, pharmaceutical residues, and regulatory limits that may change.

Important point : regulatory compliance does not mean “zero micropollutants”; traces of pollutants may be present in your tap water. Reverse osmosis lets you filter out all pollutants, which is why the water is practically "pure".

▶ Why is there so much discussion about PFAS?

PFAS, known as "forever chemicals", are a family of compounds that persist in the environment for a very long time. This topic is evolving rapidly (testing, limits, standards), and it is natural for consumers to want more control over what they drink every day.

Click here to read our article on PFAS

Misconception No. 4: “It takes up too much space”

False.

Very compact models are available, sometimes smaller than a water filter pitcher.

Misconception No. 5: “A reverse osmosis system costs too much”

False… if you make a fair comparison.

A family of 4 who drinks bottled water spends about 600 € per year.

By comparison, a reverse osmosis system requires an investment in the first year, followed by a lower maintenance cost afterward (initial investment: between 500 and 700 €, then between 120 and 180 € for maintenance).

Your investment pays for itself in 2 years.

Key takeaway: A reverse osmosis system should be evaluated as a piece of equipment: an initial investment, followed by maintenance. Over time, it costs significantly less than bottled water.

And if the initial investment feels steep, options such as rental or installment payments are available, depending on the offer.

View Josmose reverse osmosis systems →

Misconception No. 6: “It is complicated to install”

False. Installing a reverse osmosis system is often comparable to assembling a piece of furniture (such as IKEA furniture), with a clear user manual.

• Video tutorials are available to guide you through installation
• “Water dispenser” models can simplify use and installation
• Installers can provide service throughout France

▶ Tip: if you do not want to do it yourself

If DIY is not for you, choose a package that includes installation, or a "water dispenser" model that you simply plug into an electrical outlet.

Conclusion

Most misconceptions about reverse osmosis systems come from outdated information or incomplete comparisons. Today's models are more compact, more efficient, and more affordable than you might think.

Ultimately, the question is not “is it useful?” but rather: what quality of water do you want to drink every day?

FAQ – Reverse osmosis systems and misconceptions

▶ Is a reverse osmosis system cost-effective?

Often yes, especially if you buy bottled water. Compare costs over 12 to 24 months: initial investment + annual filter costs.

▶ Is RO water dangerous?

No. It has a low mineral content. If you want to adjust the mineral content (for taste or your preferences), you can add a remineralization filter cartridge.

▶ Does a reverse osmosis system filter out PFAS, pesticides, and residues?

Reverse osmosis is recognized for filtering a broad spectrum of contaminants (depending on the molecules), and is among the most effective solutions for improving water quality at home.

▶ Does it take up a lot of space?

Not necessarily: compact models are available to fit standard under-sink cabinets. The right choice mainly depends on your available space and desired flow rate.

▶ I do not want to install it myself: what are my options?

You can choose professional installation, a package with installation included, or a water dispenser solution, depending on your needs.