Hi everyone! Today let’s talk about a question from a French netizen: Does a reverse osmosis membrane remove minerals from water?

The answer is yes! Around 99% of the minerals get filtered out.

But what really matters is the deeper questions behind this: If reverse osmosis water takes away the minerals our bodies need, will it cause these problems?

First, is it bad for our health if we drink RO water for a long time?

Second, can an ultrafiltration filter prevent too many minerals from being removed?

Third, how do we choose between an ultrafiltration water purifier and a reverse osmosis water purifier?

Let’s start with the first question.

People worry that reverse osmosis membranes filter almost everything out of the water. They wonder if drinking pure water long-term will affect our mineral intake.

The truth is: tap water is not our main source of minerals. We get most of our calcium, magnesium and other minerals from meals, milk, vegetables and fruits. The minerals we get from drinking water are only a tiny amount. For healthy people, drinking pure RO water every day will not cause calcium deficiency or malnutrition.

Now the second question.

Yes, ultrafiltration filters keep all dissolved minerals in the water.

Then why do people still buy reverse osmosis water purifiers if ultrafiltration can keep minerals?

These two technologies work very differently. Ultrafiltration keeps dissolved minerals, but it cannot remove heavy metal ions, small harmful molecules, or limescale-causing ions.

Reverse osmosis membranes can block heavy metals, calcium and magnesium ions that cause limescale, chlorine by-products, nitrates, small harmful pollutants, most bacteria and viruses, and dissolved salts.

So how should we choose a water purifier for home use?

• If the local tap water has heavy metal risks or very serious limescale problems: choose a reverse osmosis (RO) water purifier to guarantee drinking water safety.

• If the local tap water quality is generally good: an ultrafiltration system combined with activated carbon is enough for daily use.