No back-to-school rush due to the holiday period

Myth: Water softeners lead to increased bacterial growth and a risk of Legionella

Water softeners prevent limescale build-up in your water pipes and household appliances. Limescale is an ideal breeding ground for bacteria such as Legionella. A water softener therefore actually prevents bacterial growth!

But what happens if you’re away from home for a long time? As we know, water that has been standing for a long time always leads to increased bacterial growth, which significantly increases the risk of Legionella. Normally, water only remains stagnant for long periods if you are away from home for a considerable time, for example whilst on holiday.

Holiday and hygiene mode

That is why we recommend that you thoroughly flush out the pipes in your home when you return. This flushing also applies to most water softeners, such as the non-electric types. However, it does not apply to water softeners that beautiful water delivers! All our models feature a so-called “Holiday Mode”, which ensures that, whilst you are away, the resin is regularly flushed with clean water, just as if you were at home. Water consumption remains very low; just a few litres a week are sufficient. This important feature is therefore included as standard with our water softeners, whilst many competing products lack it.

Automatic flushing

And in the unlikely event that you forget to switch on the holiday mode (this isn’t possible with our Excellence range, as it happens automatically), you can carry out a forced flush as soon as you get home and also thoroughly flush out your pipework with the hottest water possible for a few minutes.

Kassa water softener

In the TV programme Kassa broadcast on 1 April 2023, several incorrect statements done. Among other things, regarding bacterial growth. The programme’s producers made it clear that they were unaware of the state of the art in the latest water softeners. The programme incorrectly claimed that a water softener would promote bacterial growth. With the latest water softeners, however, the likelihood of this happening has become very small indeed. 

Study into bacterial growth in water softeners

As the rest of the world has been using water softeners for decades (with tens of millions of installations and for much longer than in the Netherlands), extensive research was carried out at the end of the last century into bacterial growth in water softeners in those countries. The conclusions are unanimous: water softeners do not lead to exponential bacterial growth and therefore pose no threat to public health. For example, in 2000, the British researcher Simon A. Parson conducted a new study into water softeners using ion exchangers. The study can be read here: (The effect of domestic ion-exchange water softeners on the microbiological quality of drinking water – ScienceDirect).

The case study presented in Kassa There was only one household where the water was not tapped immediately after passing through the water softener. It is therefore completely impossible to determine where the bacterial growth originated. This should absolutely not be called a “study”.

In addition:
1. As all our water softeners are fitted with a hygiene mode, bacterial growth is effectively ruled out. It may be that the scientists mentioned are not fully aware of the latest technological developments in water softeners
2. Limescale build-up in all the pipes, the shower head, the taps, the coffee machine, etc., also leads to an extreme increase in surface area and a significant roughening of the surface. This is completely ignored. So when we talk about the likelihood of bacteria, such as Legionella, adhering and therefore multiplying, limescale build-up really does play a major role. However, with a water softener, limescale no longer forms anywhere and everything remains clean and smooth. We have already discussed this with Professor Van der Hoek in Delft. Despite his commitment to commission research into this and repeated requests on our part, he has, unfortunately, never responded again.
3. Every few days, the water softener is flushed with a 100% brine solution. This brine contains the maximum amount of salt that water can absorb. The Dead Sea (with an average salinity of 33%) is nothing in comparison. Not a single bacterium survives this rinse cycle.

Misconceptions about water softeners

In the same episode of Kassa, further inaccurate statements were made about water softeners. See: Kassa makes incorrect statements about water softeners

Is a disinfection module required for a water softener?

Some suppliers use a system in which the resin beads undergo additional treatment involving the production of chlorine. It certainly sounds impressive, but it is actually a pointless extra, as this chlorine treatment only takes place during the regeneration of the water softener.

This disinfection module produces chlorine through electrolysis regeneration salt during the regeneration process. The chlorine then disinfects the resin column, which is supposed to prevent bacterial growth. But this is nonsense, because this chlorine treatment only takes place during regeneration. And regeneration only takes place when you use water, whereas bacterial growth can actually occur when you aren’t using any water. In fact, if you’re away for a while – such as on holiday – there’s a high chance that the first regeneration cycle won’t take place until you’ve been back home for several days. You’ll then be using water that’s passing through a water softener that hasn’t been flushed for weeks.

So, a disinfection module sounds like a good idea, but if you think it through, a very different picture emerges. That’s why at Mooiwater we say: “prevention is better than cure”.

Premium models do, however, feature a chlorine module

That said, our Premium models do come with a chlorine module. That’s right – sometimes customers do want one after all. And at Mooiwater, the customer is always king. (But in principle, it isn’t necessary.)

Questions about bacterial growth in water softeners

Do you have any further questions about bacterial growth and the water softener, or do you have any other questions? Please feel free to let us know. We’ll be happy to answer them.