Less hard water and soft water are not the same thing

HOFOR wants to make the capital's water less hard, but there is still a long way to go to soft water. If you want to avoid limescale problems , it is not necessary to change the natural composition of the water at all.

Many Danes, especially on Zealand, struggle with daily life limescale problems due to the hardness levels of their tap water.

Therefore, it also attracted the attention of some media when, shortly before January 2022, the capital's utility company HOFOR announced further plans to lower the hardness levels in the water from some of the waterworks in and especially around Copenhagen that supply the capital's citizens with water.

WE SHOULD BE INTERESTED IN water quality

There are different reactions when it comes to the Danes' attitude towards water hardness. Either they don't give it a second thought, or they fill limescale problems a lot in everyday life, once you get used to them.

IN LAGUR We think that the Danish water quality is an extremely important topic that we Danes can only take a little interest in.

But since our start in 2014, we have also been passionate about showing the Danes that there is another, non-chemical way to get rid of limescale problems on top of central water softening (waterworks) or decentralized water softening (a conventional water softening plants in the home).

LAGUR PRESERVES THE NATURAL COMPOSITION OF WATER

A LAGUR -system does not remove the lime from the water, but converts the structure of limescale from sharp crystals (the property that makes water stick) to round granules that do not deposit on surfaces and in installations to nearly the same extent as untreated water.

In addition, our solution preserves the healthy, natural composition of the water, which not least means the healthy limescale and all the good minerals, and LAGUR does not increase the sodium content of the water, which is otherwise the consequence of a water softening plants , which uses salt in the process.

HOW HOFOR WILL REDUCE HARDNESS

HOFOR will reduce the hardness of the water through the so-called pellet method. In short, the pellet method makes water less hard by adding sodium hydroxide (NaOH) and disinfected sand to the groundwater. Part of the lime is bound to the sand grains, which become small lime pellets that sink to the bottom and can be removed. This reduces the lime content in the water that is to be delivered to consumers.

The method is quickly referred to as a ' water softening plants ', and the goal is described as 'softer water', which is also correct if what you want is less hard water.

'HARDNESS REDUCTION PLANT'

On the other hand, 'soft water' has a long outlook, and in most places residents will therefore still have limescale problems on tiles, fixtures and in installations after the pellet method has been introduced.

The systems for private individuals that are marketed in Denmark as ' water softening plants ', in Germany, where they are often produced, are referred to as 'Wasser Enthärtungsanlage' (water hardness reduction plant), because it is more comprehensive and correct.

Likewise, the term for hardness, dH, that we use for hardness in Denmark, comes from Germany (Deutsche Härtegrade).

HARD WATER FROM NATURE

So-called 'soft water', however, has a hardness of just 4-8 dH, while 0-4 is 'very soft', 8-12 is 'medium hard', 12-18 is 'fairly hard', 18-24 is 'hard', 24-30 is 'very hard', water above 30 dH is 'very hard'.

From a natural point of view, the water in the capital area generally has a hardness of 20-30 dH, so it makes good sense to do something to reduce the hardness centrally at the waterworks. But there are limits to how far down the hardness can go when the starting point is so hard.

In Brøndby, where HOFOR's first pellet plant has been in operation for a few years, the official hardness value is now 10-14 dH. 14 dH is a big improvement, but the water is still 'pretty hard', and citizens with tap water in this hardness category know how many limescale problems that can still be in everyday life.

WATER IS HARDEST IN THE EAST

We only find soft water from nature in a few places in Central and Western Jutland, and in general, the hardness increases the further east we go.

See a map of Danish water hardness here.

According to HOFOR's ambitious plan, there will be a dozen waterworks that use the pellet method to reduce water hardness by 2028. Together, they will supply approximately 75 percent of the drinking water from the capital area's utility company, according to HOFOR.

The rest of the water will come from other water supplies, including from smaller boreholes in North Zealand, where the water hardness will not be lowered.

SALT CAN BE OMITTED COMPLETELY

There will therefore still be a need for decentralized systems for private individuals who want to limit limescale challenges in their homes.

HOFOR itself mentions that one of the benefits of central ' water softening ' using the pellet method, less salt is consumed in decentralized water treatment plant That is correct – to the extent that consumers use conventional chemical water treatment plant with salt.

IN LAGUR On the other hand, we have chosen to treat the water completely without the use of chemicals, so that the healthy properties of the water by virtue of limescale and minerals are preserved, while the calcium discomfort for consumers is still minimized.