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Salt-free · CO2-based · certified drinking water

Goodbye limescale. No salt. No waste.

SoluCalc injects food-grade CO2 into your water, turning calcium carbonate into soluble bicarbonate — no limescale on your appliances, no sodium in your drinking water, no brine discharge in your garden.

Estimate my savings Free on-site visit
5-year warranty ~2h installation ACS · CE · Buildwise
SoluCalc device photo
Replace via builder · recommended 800×600px · hero shot of the 1" unit wall-mounted

How it works

A compact device installed after your water meter injects a precisely controlled dose of food-grade CO2. The chemistry does the rest — limescale dissolves instead of building up.

Diagram: how the CO2 injection works
Replace via builder · schematic or photo of water line, CO2 cylinder, SoluCalc unit + arrows

Chemistry, not physics

Other softeners swap calcium for sodium (ion exchange). SoluCalc leaves the calcium in your water but transforms it chemically so it can't stick to surfaces. Result: no salt, no waste, minerals preserved.

Verified effective up to 95°C — works in boilers, DHW tanks, heat exchangers.

Food-grade CO2

Precisely dosed, safe for drinking water, 10 kg per year typically.

Minerals preserved

Calcium and magnesium stay in your water — no added sodium.

Zero waste

No regeneration brine, no wastewater, no salt to carry up stairs.

No maintenance

Just annual CO2 refill. No regeneration checks, no salt-level worry.

Estimate your yearly savings

Three inputs. The rest is math.

Estimates based on SoluCalc field data: ~25% boiler efficiency gain at hard water, reduced detergent use, longer appliance life.

Estimated yearly savings
€285
for a typical 4-person household in hard water
  • Boiler efficiency gain (25% × hot water cost)€165
  • Detergent + cleaning products reduction€60
  • Appliance lifespan extension (amortised)€60
  • Total yearly savings€285

Net of CO2 cylinder refill cost (~€60/yr residential). Savings vary — your installer confirms on the free on-site visit.

Get a precise quote

SoluCalc vs salt water softener

Same problem, two different philosophies.

Criterion Salt water softener SoluCalc (CO2)
Sodium in drinking water Adds sodium No added sodium
Salt / CO2 consumption 100–200 kg salt/year 10 kg food-grade CO2/year
Wastewater Up to 3,000 L brine/year Zero brine, zero discharge
Footprint Large brine tank + salt reservoir Compact unit + CO2 cylinder
Maintenance Monthly salt refill Annual CO2 refill, delivered

Two models, one for every building

SoluCalc 1" product photo
Replace via builder · 600×400px · residential unit

SoluCalc 1"

Residential · up to 8-unit buildings

from €1,900 HTVA

device only · installation ~2h

  • Flow: up to 5 m³/hour
  • CO2 consumption: ~10 kg/year
  • Compact wall-mount, after water meter
  • Needs 220V outlet nearby
Request a quote
SoluCalc 2" product photo
Replace via builder · 600×400px · commercial unit

SoluCalc 2"

Multi-residential · commercial · industrial

from €4,200 HTVA

device only · installation 3–4h

  • Flow: up to 20 m³/hour
  • CO2 consumption: 20–40 kg/year
  • Hotels, schools, apartment buildings, industrial sites
  • References: IKEA, Decathlon, Brussels Airport
Request a quote

Frequently asked questions

Based on SoluCalc's official FAQ.

Operating principle
How does it work?
The system injects a controlled amount of CO2 into the water. This converts dissolved calcium carbonate into soluble calcium bicarbonate, preventing limescale from crystallizing and sticking to surfaces.
Has the principle been validated independently?
Yes. The operating principle has been tested and validated by independent laboratories according to recognised European standards.
No salt and no regeneration, correct?
Correct. The system uses no salt, requires no regeneration cycles, and discharges no wastewater.
Will the water be carbonated (sparkling)?
No. The injected CO2 reacts chemically with limescale; it does not remain as free gas, so the water is not carbonated at the tap.
Will my water still be drinkable?
Yes. The water remains fully drinkable and compliant with drinking water standards. Minerals (calcium, magnesium) are preserved.
Why doesn't the water hardness number change?
The system does not remove calcium or magnesium; it keeps them dissolved in a non-scaling form. Your measured hardness stays the same, but the scale disappears.
Will I feel the difference on my skin and hair?
Most users report softer skin and hair because limescale deposits are reduced and soap rinses more easily.
Does the CO2 escape at the tap, making treatment ineffective?
No. CO2 dissolves to form carbonic acid, reacts with limescale before reaching the tap, and remains effective in water up to 95°C (hot water circuits).
Any corrosion risk?
When correctly adjusted at installation, the system keeps the water in a balanced state and does not increase corrosion risk.
CO2
Is CO2 dangerous?
No. CO2 is a natural gas already present in drinking water. The quantities used are low and safe.
How do I know when the cylinder is empty?
The system has a pressure indicator that shows when the CO2 cylinder needs replacement.
How much CO2 does it use?
Consumption depends on water use and hardness. Typically one cylinder lasts several months in a household installation (≈10 kg/year for a 1" unit).
How much does CO2 cost?
CO2 cylinders are low-cost: typically a few euros per month for a household (≈€50–€70 per year). Ecowatt delivers them as part of the service.
Appliance & installation
Is maintenance required?
No regular maintenance is required apart from periodically replacing the CO2 cylinder.
What is the warranty?
5-year manufacturer warranty on the device. Ecowatt also provides local after-sales service and parts.
Which model is right for me?
SoluCalc 1" for single homes up to 8-unit buildings (flow ≤ 5 m³/h). SoluCalc 2" for multi-residential, commercial, industrial (flow ≤ 20 m³/h). We size it during the free on-site visit.
Who installs the system?
Installation is performed by SoluCalc-trained installers. Ecowatt is a certified installer for the Brussels–Flemish Brabant region.
Is SoluCalc compatible with my activated carbon filter?
Yes. Both systems are compatible and complementary. Carbon filters refine water taste; SoluCalc protects the whole installation from limescale.
Compatible with reverse osmosis?
Depends on placement. Under-sink RO: fully compatible. Whole-home RO at main entry: CO2 injection must be installed AFTER the RO membrane.
Can I use less detergent?
Yes. Reduced limescale improves the effectiveness of soaps and detergents, often allowing 20–30% lower consumption.
Suitable for a hair salon, hotel, school?
Yes. Commercial SoluCalc 2" units are deployed in hair salons, hotels, schools, hospitals, and industrial sites. References: IKEA, Decathlon, Brussels Airport.

Why install SoluCalc with Ecowatt

  • Certified installer — trained by SoluCalc, clean install, commissioned on the spot.
  • HVAC expertise — we understand how scale affects your boiler, heat pump and bathrooms. We size the unit right the first time.
  • Bundled with maintenance — add SoluCalc CO2 refills to your Ecowatt maintenance visits. One technician, one schedule, one invoice.
  • Local team — Vilvoorde-based, trilingual, familiar with Brussels hard water.
When SoluCalc makes sense
  • Your water hardness is above 25°F (common in Brussels + most of Flanders).
  • You're replacing an old salt softener that discharges brine.
  • You're doing a bathroom reno or new installation — install SoluCalc first, save the new fixtures.
  • You have a co-ownership and want a low-maintenance, quiet solution.

Start with a free on-site visit

We check your water hardness, size the right unit, and quote — no obligation.

Book a free visit +32 15 62 70 80