In other words: what minerals are, and who needs them.
At first glance, drinking water can seem like a rather boring topic. Tap water should be drinkable, and if you don't like the taste, you buy bottled water or use a filter jug. Luckily, water is never just water: it also contains minerals that matter to us. Let's look at what these minerals are, why we need them, and how your drinking water can be clean AND contain minerals at the same time.
What do Tallinn tap water and Evian have in common?
The same word, "water", means quite different drinks on the supermarket shelf and at the tap. Most people have never really thought about it, because it isn't talked about enough. Besides, many of us only start looking into health topics once the first problems appear.
Let's take a closer look at three popular waters.
Three waters, minerals in milligrams per litre
| Water | Calcium (Ca) | Magnesium (Mg) | Sodium (Na) | Potassium (K) |
|---|---|---|---|---|
| Evian | 80 | 26 | 6.5 | 1 |
| Värska Originaal | 116–129 | 40–44.5 | 605–670 | 19.5–21.5 |
| Tallinn tap water* | 80 | 8 | 9.1 | 2.35 |
* Measured at the water treatment plant, before the pipe network, 08.06.2026.
Tallinn tap water contains exactly as much calcium as Evian, which is good news for anyone who has carried Alpine water home from the shop. The other minerals, however, differ a lot. Tap water has three times less magnesium. Värska Originaal contains about a hundred times more sodium than Evian, because sodium is a component of salt and Värska mineral water is naturally salty.
Why do we need minerals at all?
We get most of our minerals from food. Water is a secondary source, but we all drink it every day, for our whole lives.
- Calcium is needed for the maintenance of normal bones.
- Magnesium contributes to the reduction of tiredness and fatigue and to electrolyte balance.
- Potassium contributes to normal muscle function and to the maintenance of normal blood pressure.
- Sodium is a component of salt and is lost through sweat. You lose the most after sport, a hike or the sauna.
What else does tap water contain besides minerals?
Tallinna Vesi regularly publishes drinking water analyses, and the results are generally within the limits. Chlorine is added to tap water to keep the pipes clean. In the June sample, free chlorine was 0.63 mg/l (limit 1) and chlorine by-products, trihalomethanes, were 57 µg/l (limit 100). That's the faint swimming-pool smell you notice when you turn on the tap. The sample was taken at the treatment plant, so whatever the pipes add on the way to your glass isn't included.
But routine analysis doesn't measure everything. In February 2025, Sküma had a COFRAC-accredited French laboratory test 229 substances found in drinking water. The tested water contained chlorine and its by-products, heavy metals, PFAS, pesticides, pharmaceutical residues and microplastics. Not something we'd want to consume every day.
Bottled water isn't the answer either. A 2024 Columbia University study found an average of 240,000 plastic particles per litre in US bottled water, most of them nanoplastics. And the mineral content depends on the product: some have plenty, some very little.
No microplastics, please!
Today, the most effective technology for removing contaminants is reverse osmosis. But it makes water so pure that nothing is left except water: no magnesium, calcium or potassium. It quenches thirst as well as any other water, but it provides no minerals.
The World Health Organization report "Nutrients in Drinking Water" (2005), co-authored by Czech scientist František Kožíšek, advises against drinking such demineralised water as your only drinking water over a long period. According to the report, drinking water should contain 20–30 mg of magnesium and 40–80 mg of calcium per litre.
So what is perfect drinking water?
Water that supports your health: clean, but with minerals. The safest, highest-quality water is water purified by reverse osmosis, with minerals added back. Sküma's reverse osmosis removes 99.9% of contaminants and adds minerals back in the perfect ratio. You choose the mineral blend yourself, based on your goals and lifestyle:
- Mineral Soft is everyday water for the whole family.
- Mineral Plus is for when you move a lot and sweat. It has the most magnesium.
- Mineral Alkaline raises the water's pH by about one point and has the most potassium.
Sküma mineral blends, milligrams per litre
| Mineral blend | Magnesium | Calcium | Potassium |
|---|---|---|---|
| Mineral Soft · for the whole family | 18 | 1.4 | 1.3 |
| Mineral Plus · when you move and sweat | 29 | 0.8 | 9.6 |
| Mineral Alkaline · pH 8.5 | 3.0 | 4.1 | 125 |
According to the MY Bases packaging, converted per litre.
The mineral blends were developed in Europe together with Robertet Group, which has 175 years of experience with natural raw materials.
If you want to be sure about your drinking water and don't want to compromise on taste, Sküma may quickly become your new and rather indispensable friend. The only risk is that you might turn into a water snob and hydration gourmet, because people get used to good taste and feel very quickly, and not every water will do afterwards! 😄
Sources
- WHO (2005). Nutrients in Drinking Water. F. Kožíšek, "Health risks from drinking demineralised water"
- evian.com, product composition
- varskaoriginaal.ee, Värska Originaal composition
- AS Tallinna Vesi Laborid, analysis report VL-26-296, Järvevana tee 3, sample 08.06.2026
- aquasisters.ee/pages/teadus, COFRAC-accredited laboratory, February 2025
- Qian et al. (2024), PNAS 121(3), Columbia University
- MY Bases packaging (Mineral Soft, Plus, Alkaline)