What to consider when choosing a water softener
The catalog of water softeners is extensive, and prices of seemingly similar devices can differ by as much as twofold. To avoid buying blindly, it's worth comparing models based on five criteria:
- Capacity (flow rate, m³/h) The softener must handle peak water demand, not just average consumption. For an apartment with one bathroom, 1.0–1.5 m³/h is usually sufficient; for a house with 2–3 draw-off points used simultaneously, 1.8–2.5 m³/h. Insufficient capacity means a pressure drop when water is running in several places at once.
- Resin bed volume (l) This determines the filter cycle – how much water the device processes between regenerations. The harder the water and the greater its consumption, the larger the required resin tank.
- Control head This element is largely responsible for the price difference between devices and determines their reliability. We elaborate on this below.
- Type of ion-exchange resin Standard or monosheric, regular or multi-functional – affects efficiency and what impurities the softener removes. We also elaborate on this below.
- Service availability and real operating cost It's worth checking if spare parts and service for the chosen model are readily available in the long term, not just during the warranty period. The real cost is not just the purchase price, but also salt consumption and potential service costs in subsequent years.
The first two points will be calculated for you by the calculator above. However, it's important to understand why the other three so significantly affect price and effectiveness – especially the control head and resin.
Control head: what to look for
The control head initiates regeneration, doses the brine, and after years is usually the first to require service – which is why its design, alongside the resin bed itself, largely accounts for the price difference between seemingly similar devices.
In our offer, you will find two approaches:
Clack, Runxin
Pros: Spare parts and service independent of the device brand; usually, individual components (e.g., piston, seals) can be replaced rather than the entire module; simple, clear configuration.
Things to watch out for: Usually fewer advanced additional features (e.g., remote control via app) than in selected proprietary solutions.
Electrolux, EcoWater, Aquaphor, Ecosoft
Pros: Electronics optimized for a specific model, sometimes with additional features (e.g., salt-saving algorithms, Wi-Fi connectivity in selected models); consistent manufacturer warranty for the entire device.
Things to watch out for: Service and spare parts are tied to the device brand, not an independent service network.
Neither of these approaches is universally "better" – it's a matter of whether you value independent service more or the additional features of a specific manufacturer. Both types of heads in our offer work for years with regular, basic maintenance (salt control, seals).
Ion-exchange resin: not all resins do the same thing
The volume of the resin bed is only half the story – equally important is the type of resin working within it, as this determines what the softener actually removes from the water.
Dowex HCR-S/S
Strongly acidic cation resin. In our offer: Electrolux, Anthracite Azure. Removes only calcium and magnesium.
Lewatit S1567
Uniform granules result in lower water consumption for resin rinsing. In our offer: Supreme Clever.
Ecolite Soft / Ultrasoft
Ecosoft's proprietary resins. Standard version: Core, CUBE. Ultrasoft (Arctic Blue) tolerates up to 15 mg/l of iron at the inlet without rapid fouling – this is iron resistance, not its removal.
Ecomix®
In our offer: Anthracite/Titanium Gold, ECOMULTI. In addition to hardness, they also remove iron and manganese, and selected varieties also remove organic compounds and ammonia.
KDF85
In our offer: "P1 with KDF85" versions of the Aquaphor line. Does not soften water itself – additionally reduces hydrogen sulfide.
It's also worth knowing that almost exclusively cationic resins are used in domestic water – they remove positively charged ions (calcium, magnesium, iron, manganese). Anionic resins, which remove nitrates or sulfates, for example, are rarely used in home installations, mainly in specialized applications.
In our calculator, questions about iron, manganese, and other impurities are not accidental – they determine whether you need a standard resin or a multi-functional bed. Manufacturers usually state the exchange capacity of the resin in gram-equivalents per liter (g-eq/l) – this, along with the bed volume, allows you to calculate the real ion-exchange capacity of the entire device (see section below).
How to read a softener's data sheet
Manufacturers present data in various ways and with varying degrees of detail, but three numbers are always worth looking for and comparing between models – the rest are usually extras.
Ion-exchange capacity (m³×°dH)
How many cubic meters of water at a given hardness the device will treat between regenerations. This is the number to compare models – not just the bed volume in liters, which with different resins gives completely different real capacities (as seen above: 15 l of monosheric resin can hold as much as 25 l of ordinary resin).
Operating flow rate (m³/h)
Must cover peak demand in the home, not just average consumption – otherwise, pressure will drop when water runs in several places at once.
Brine tank capacity (kg)
Indicates how infrequently salt needs to be added – this is a different number from the frequency of regeneration itself, which can easily be confused.
The relationship between them is simple: daily water consumption (m³) multiplied by its hardness (°dH) gives the daily bed load. The ion-exchange capacity divided by this load is the approximate number of days between regenerations. This is precisely the relationship that the calculator above uses. Treat the result as a good starting point for discussion with us, and not a definitive, 100% precise answer.
Well water: a calculator cannot replace laboratory analysis
For municipal tap water, data from the water utility and an approximate hardness test are sufficient. For well water, the situation is different – no one tests this water for you, and a simple hardness measurement says nothing about iron, manganese, or other compounds that may require a completely different device selection than a standard softener.
How to measure hardness itself is described in a separate article – and general guidelines for selecting a softener for a well can be found in our complete guide. If you already have the results of a full water analysis – the calculator will use it for a more accurate selection.
Frequently Asked Questions
Why do softeners with similar bed capacity vary so much in price?
Most often, this is due to the quality of the control head and the type of resin – not just the brand of the device. Models with an independent service head and monosperic resin cost more than budget counterparts, but they translate into longer, easier-to-service operation.
Which models in your offer have a Clack head?
Clack in our offer comes in three variants: WS1CK (Supreme Clever), electronic DV (Ecosoft Core), and advanced CE (Ecosoft Arctic Blue). Ecosoft CUBE models use the Runxin F105B head. Other brands (Electrolux, EcoWater, Aquaphor) use their own integrated electronic heads.
Does every ion-exchange resin work the same way?
No. Standard resin (e.g., Dowex, Lewatit, Ecolite Soft) only removes water hardness, multi-functional beds like Ecomix additionally remove iron and manganese, and modules with activated carbon or KDF remove selected additional impurities – each different.
Does a softener with KDF85 remove heavy metals?
Usually not, even though general descriptions of KDF85 online suggest it. A different variety of the medium – KDF-55 – is responsible for heavy metal reduction. Our models with KDF85 (Aquaphor P1) are officially described by the manufacturer as reducing hydrogen sulfide, not heavy metals – which is why the calculator does not show this option for these models.
Does the calculator replace laboratory water testing?
No, especially for well water. This is a preliminary, approximate selection based on your answers – for unusual parameters, we recommend a full analysis and contacting us.
Where does the data in the calculator come from – is it just an averaged formula?
No. The calculation is based on the actual ion-exchange capacity (m³×°dH) of specific models from manufacturers' data sheets – exactly the number we describe above in the "How to read a softener's data sheet" section.
What if no model matches my answers?
This happens in very unusual conditions. The calculator will explicitly state this and suggest contacting us for an individual selection.
How long does it take to fill out the calculator?
About 2 minutes – 8 simple questions, without the need to provide contact details.
