Javascript is disabled in your browser. Please enable it to use this website.

How a water softener works in detail

Jun 25, 2024, 9:06:17 AM

How is limescale removed from drinking water?
What properties does softened water have?
What happens when the water softener is regenerated?

Our water softening systems (also known as decalcification systems) work with the ion exchange process. This is a chemical process that removes the hardness-forming calcium and magnesium from the water and replaces them with easily soluble sodium (a component of salt).

How is limescale removed from drinking water?

Strictly speaking, limescale is only what remains when very hard water evaporates. It consists mainly of calcium and magnesium. Our water softening systems are installed in the house installation near the water meter. The hard drinking water supplied by the waterworks flows through the control valve from top to bottom through the ion exchange resin, which is located in the system's pressure tank. The water is softened in this area. The exchange resin is designed in such a way that it absorbs calcium and magnesium ions and leaves sodium ions behind in the water.

Once the water has reached the lower part of the water softening system, it flows back up through a riser pipe. Special filter nozzles, which are attached to the top of the control valve and the bottom of the riser pipe, ensure that the special resin remains in the pressure vessel. This means that the limescale remains in the system's pressure vessel and clean, limescale-free water leaves the system into your house's pipes.

(Image: Duplex water softener )

What properties does softened water have?

The water that can be taken from a water softener has a water hardness of 0° dH or 0 mmol/l. This means that there are no more limescale-forming substances in this water (all other substances remain untouched). The pH value is unchanged compared to the incoming water, as the ion exchange process is a neutral exchange process. The sodium content increases by around 8 mg per liter and per degree of hardness removed in °dH. So if you previously had a water hardness of 20 °dH, then after softening you will have 160 (20 x 8) mg per liter more sodium in your water than before. The limit for sodium in drinking water is 200 mg per liter.

Fully softened water is suitable for drinking up to a certain degree of hardness. If the water hardness is very high (over 25 °dH), a residual hardness must be left in the water if you do not want to exceed the limit for sodium. Therefore, there is the option of regulating the water hardness using an adjustment screw. For example, you can leave a residual hardness of 5 °dH in the water. This also has the advantage that you save some salt.

What happens when the water softener is regenerated?

As soon as the capacity is exhausted, the exchange resin must be regenerated in order to be able to absorb new hardness-forming substances. The control valve works fully automatically and initiates the regeneration as soon as it is necessary. During regeneration, the system is rinsed with salt brine. The exchange resin absorbs the sodium ions and releases the previously absorbed calcium and magnesium ions. The rinse water automatically ends up in the wastewater.

With single systems, regeneration usually takes place every three days, exactly when water is needed the least (usually at night). Our duplex water softening systems basically consist of two full-fledged water softening systems and work in alternating mode. This means that one softening column is always in operation, while the second is being regenerated or is on standby. This means that our duplex models have soft water available around the clock. More information: Single or double water softening system (Basic vs Duplex)

In our shop you will find the right water softener for your household.

Fitting Products