Why ‘delete everything’ isn’t the best solution

Why we retain minerals rather than remove them

There is hardly any debate in the world of water filters as controversial as the question: osmosis or not? Reverse osmosis systems are among the most powerful filtration systems on the market. They remove practically everything from the water – pollutants, germs, but also all minerals and trace elements.

At MAUNAWAI, we have deliberately chosen not to take this approach. Not because osmosis doesn’t work well – it is an impressive technology. But because we are convinced that filtration must be more than just removal. Good water is not simply water minus pollutants. It is water that closely resembles natural spring water in its properties.

How reverse osmosis works

The principle is simple: water is forced through a semi-permeable membrane under high pressure. This membrane allows water molecules to pass through, but retains practically all dissolved substances – minerals as well as contaminants. On one side of the membrane, the ‘pure’ water collects; on the other, the concentrated residues, which are disposed of as waste water.

The result: water with a TDS (Total Dissolved Solids) value close to zero. Technically impressive. But does it make biological sense?

The problem with ‘empty’ water

Demineralised water behaves differently from natural water. It lacks the internal surfaces created by dissolved minerals. Without these surfaces, the water has less energy and less structure. It is – figuratively speaking – ‘hungry’: it tends to absorb minerals from its surroundings rather than release them.

The WHO is clear on this point: desalinated drinking water should be remineralised before being used as drinking water. Studies from the Czech Republic and Slovakia documented more frequent muscle cramps, exhaustion and electrolyte imbalances in people who regularly drank osmosis water. Water low in calcium is associated with a higher risk of bone fractures in children.

An often overlooked aspect: cooking with demineralised water causes additional minerals to be lost from food. The water ‘draws’ the minerals out of the food – an osmotic effect. Studies estimate the loss of calcium and magnesium at around 60%, and for trace elements such as cobalt, even over 80%.

The TDS trap

Some suppliers of reverse osmosis systems use so-called TDS meters to demonstrate the supposed superiority of their water. These small devices measure the electrical conductivity of the water and display a numerical value: the lower the value, the ‘purer’ the water.

What is not mentioned here is that a low TDS value primarily means that there are few charged particles – i.e. minerals – in the water. This says nothing about the absence of toxins. Most pollutants, such as pesticides, hormones and pharmaceutical residues, are uncharged and are not detected by TDS measurements at all. A low TDS value can therefore mean either ‘free from pollutants’ or simply ‘low in minerals’.

The electrolysis demonstration

Public demonstrations involving electrolysis are particularly misleading. Two metal rods are immersed in the water to be tested, and an electric current is passed through it. In mineral-rich water, visibly more gas is produced and – if iron electrodes are used – a brownish discolouration occurs. This is mistakenly presented as “proof” of toxins in the water.

The truth: the reaction merely indicates the mineral content. If you add the same amount of pure table salt to osmosis water, you get exactly the same reaction. And the brownish discolouration? It comes from the rust on the iron electrodes – not from the water. With stainless steel electrodes, it does not occur.

The MAUNAWAI approach

Our approach is different: we specifically remove the harmful substances whilst retaining the valuable minerals. Independent analyses by the IIREC Institute confirm that, following filtration, MAUNAWAI water contains a balanced mineral profile – calcium, magnesium, potassium and trace elements in their natural concentrations.

What’s more: our system uses no electricity, produces no waste water and requires no salts or chemicals. A reverse osmosis system produces three to five litres of waste water for every litre of drinking water. For a four-person household filtering three litres a day, that amounts to up to 15 litres of waste water – every day.

Shelf life and taste

Another difference that is noticeable in everyday life: MAUNAWAI water has a longer shelf life than osmosis water. Mineral-rich water has more stable internal structures – the minerals form internal surfaces on which the water’s membrane substance builds up. Osmosis water lacks these internal surfaces. It cannot maintain its structure and quickly takes on the taste of the container in which it is stored.

This also explains the difference in taste: MAUNAWAI water has character – it tastes fresh, smooth and lively. Osmosis water is described by many as flat and ‘empty’.

Fairness: What osmosis does well

We want to remain fair. Reverse osmosis has its place – for example in industry, in seawater desalination or in regions with heavily polluted water, where the complete removal of all substances is the safest option. Osmosis is also the right choice for certain medical applications where absolutely pure water is required.

However, for the daily drinking water needs of a Central European household, we believe our approach is the better way. Not because osmosis is “bad”, but because the human body is evolutionarily designed for mineral-rich water – not distilled water.

Our stance

We respect what nature puts into water. We remove only what humans have added. That is our principle – and it sets us apart from every osmosis system on the market. If you would like to learn more about the importance of minerals in water, read our article “Minerals in Water” in the “Understanding Water” section.