Reverse osmosis or filter: two ways to clean water
Reverse osmosis removes almost everything from water, including the minerals. MAUNAWAI takes a different approach: contaminants out, minerals in. Here you can compare both approaches side by side.
- A reverse osmosis system forces water through a very fine membrane under pressure. What comes out is demineralised water, a technical product that does not occur in this form in nature.
- A TDS meter only measures electrically conductive substances. It cannot tell whether they are valuable or harmful.
- Reverse osmosis systems need electricity and discharge part of the water as wastewater. MAUNAWAI filters without electricity, without wastewater and without chemicals.
- Reverse osmosis has its place, for example in industry or seawater desalination. For everyday drinking water at home, we believe our approach is the better one.
Why we leave the minerals in
Few questions about water filters spark as much passionate debate as this one: reverse osmosis or not? Reverse osmosis systems are among the most powerful filtration systems available. They remove contaminants and germs, but also calcium, magnesium and trace elements.
We have deliberately chosen a different path. Not because reverse osmosis works poorly. But because, for us, good water is more than water minus contaminants. Our model is the mountain spring: clean, and still full of minerals.
How reverse osmosis works
Water is forced under high pressure through a semi-permeable membrane. The membrane lets water molecules pass and holds back almost all dissolved substances, minerals and contaminants alike. The filtered water collects on one side, and on the other the concentrate, which drains away as wastewater.
The result is water with a TDS value close to zero. Technically impressive. But the minerals are gone too.
What a TDS meter shows, and what it doesn’t
Some suppliers like to demonstrate a TDS or ppm meter: the lower the number, the “purer” the water. But the device measures only electrically conductive substances, which means mainly minerals. It cannot tell whether a substance is valuable or harmful.
An example: pour turpentine into water and the ppm reading stays the same. You still wouldn’t drink it.
So a low reading after a reverse osmosis system shows one thing above all: there are hardly any minerals left. What a filter actually removes is shown by laboratory analyses of the individual substances, not by a conductivity meter.
The MAUNAWAI way
We take out what doesn’t belong in water and leave the minerals in. For PFAS, we cite test results from a DAkkS-accredited laboratory. PI technology has been examined in a long-term study by the independent institute IIREC under Dr. Walter Medinger.
What’s more, our systems need no electricity, produce no wastewater and work without salts or chemicals.
Taste
Many of our customers describe filtered water with minerals as soft and rounded. Demineralised water, on the other hand, tastes flat to many people. Try it for yourself, with a 30-day money-back guarantee.
To be fair: what reverse osmosis does well
Reverse osmosis has its place, for example in industry, in seawater desalination or where water is so heavily contaminated that everything has to come out. For everyday drinking water in a household in Central Europe, we consider our approach the better way.
Our position
Contaminants out, minerals in. We have been filtering by this principle since 1996, from the jug to the whole house. Read more about minerals in water in our “Understanding Water” section.
Written by Daniel Knoch