Water purifiers are usually talked about in one of two ways. Either you get a list of technical abbreviations nobody understands, or vague promises about health. Let's try a third way and simply explain what actually happens to your tap water as it passes through Sküma.
The question we've been getting most often lately is: what does this device actually do? The answer has three parts — purify, remineralize, use.
BEFORE THE WATER REACHES THE UNIT
Estonian tap water meets the requirements. That means the legal limits set for drinking water are met. It doesn't mean the water contains nothing but H2O.
On its way from the treatment plant to your tap, water travels through a long pipe network. In older buildings it picks up rust, limescale, lead, and copper along the way. Chlorine is used for disinfection — necessary and sensible — but chlorine by-products remain in the water. On top of that, PFAS substances, microplastics, and pesticide and pharmaceutical residues have been found in tap water across Europe, substances treatment plants don't fully filter out.
That's not a reason to fear tap water. It's a reason to know what you're drinking.
PURIFY
The first step is the logical one — we purify the water. The Sküma Super Filter cartridge combines three filtration stages.
The PP sediment filter catches larger particles: sediment, rust, sand. Without it, the next stages would clog quickly.
The activated carbon filter — quality activated carbon binds chlorine, chlorine by-products, and organic compounds that give water an off-taste and smell. Most pitcher filters stop at this stage, which is exactly why heavy metals and PFAS substances pass right through them.
The reverse osmosis membrane — the membrane's pores are so small that essentially only water molecules can pass through. Heavy metals, PFAS substances, microplastics, and pesticide and pharmaceutical residues are left behind.
SKÜMA IS SCIENCE-BASED
Sküma has its units tested by an independent lab. In February 2025, a COFRAC-accredited French lab tested 229 substances in total — the same accreditation trusted by hospitals, pharmaceutical labs, and food safety authorities.
Tap water before and after Sküma:
- Heavy metals: 253 µg/l → below 3.2 µg/l, removed 98.7–99.9%
- PFAS, 20 compounds: 1792 µg/l → below 0.056 µg/l, removed 99.9%
- Microplastics: 316 particles → 6 particles, removed 98.1%
- Pesticides, 165 types: 1.386 µg/l → 0.022 µg/l, removed 98.3–99.9%
- Pharmaceutical residues: 0.025 µg/l → below 0.004 µg/l, removed 86–99.9%
- Volatile organic compounds: 0.28 µg/l → below 0.13 µg/l, removed 53.9–99.9%
- Fluoride: 0.59 mg/l → below 0.1 mg/l, removed 83.1–99.9%
- Total chlorine: 0.08 mg/l → below 0.04 mg/l, removed 99.9%
In total, 99.9% of contaminants and 98% of microplastics are removed. All results are on the science page: aquasisters.ee/pages/teadus
What's left behind by the membrane goes into the wastewater tank. Depending on how hard your tap water is, this is roughly a quarter to a third of the water put in. The tank should be emptied when the unit shows the "Empty Waste" notification — and that water is great for houseplants.
REMINERALIZE
This is where most water purifiers leave the job half done.
Reverse osmosis is thorough, and unfortunately water can't be purified selectively. So the Super Filter also removes the magnesium, calcium, and potassium we need. The result is "empty" water that doesn't effectively maintain our fluid balance. The same goes for most bottled water, where mineral content is minimal anyway.
This is exactly where Sküma is unique — its remineralization system. Most water devices leave the water empty and expect you to add the right minerals back yourself. But how much and which minerals to add is its own science, requiring thorough research and precise dosing.
Sküma was created by biohackers and water industry specialists who worked with longevity doctors to develop precisely balanced mineral blends. That's exactly why we're confident promising that you'll start drinking perfect water.
There are three profiles.
Mineral Soft — a soft, neutral blend for everyday drinking water. Clean, simple water for the whole family.
Mineral Plus — a higher-mineral blend, suited to summer months, training periods, and times when you're active or sweating a lot.
Mineral Alkaline — a balanced blend with pH 8.5, pleasant alkaline water. Raises the water's pH by about one point. Good for recovery after both workouts and a night out.
You can switch profiles whenever you like and keep several going at once in different bottles. The minerals are heat-stable, so they don't break down whether the water is hot or cold.
WHAT A LITER COSTS
One mineral pack makes 40 liters of water; each package contains four sachets, for 160 liters total.
- Mineral Soft, €41 → €0.26/liter
- Mineral Plus, €46 → €0.29/liter
- Mineral Alkaline, €51 → €0.32/liter
Add the filter: €51 divided across 750–1100 liters comes to €0.05–0.07 per liter.
In total, perfect, plastic-free water mineralized to an exact recipe costs you roughly 31–39 cents per liter — and you never have to haul cases home or return bottles for deposit.
USE
Now the practical side. The Sküma tank holds 4.8 liters and you fill it yourself, so no plumbing is needed. The unit always has about 1.5 liters of ready water on hand, and refilling takes 5–8 minutes depending on your tap water quality.
Honestly, Sküma isn't quite "unbox and drink" — before your first glass, the filter needs to be locked in with the installation key and the system flushed through twice. This takes about 20 minutes and you only do it once. All steps are in the user manual.
After that, you just press a button.
Temperatures: cold, 50°C, 75°C, 85°C, Max Volumes: 250 ml, 350 ml, 500 ml, 1000 ml, continuous
Green tea wants cooler water than black tea, and the highest setting is better for coffee than boiling water. The unit doesn't cool water — "cold" means room temperature, so for truly cold water keep a glass jug in the fridge.
MAINTENANCE, NO SURPRISES
One Super Filter lasts 750 to 1100 liters, depending on how hard your water is. Estonian water is mostly hard, especially in northern Estonia, so plan for closer to 750 liters — for two people, that's roughly a year. You'll get the best water quality by changing the filter every 8–10 months.
Three signs it's time: making water takes noticeably longer than usual, the water's taste has changed, or it's been 8–10 months since the last change.
Limescale should be removed every 12–16 weeks, or after a longer shutdown of more than eight weeks. The maintenance kit includes everything needed for this.
And when the old filter comes out, don't throw it away — send it back to us and we'll take care of 100% recycling.
SUMMARY
A pitcher filter removes some substances. Mineral drops add some back. Sküma does both in one unit, has the result independently verified in an accredited lab, and leaves the choice up to you — which profile ends up in the glass is still your call.
As they say: go with the flow. All water leads to Sküma eventually.