Is a central water filtration system useful (descaling)?

that has absolutely nothing to do with the topic here.... but oh well. How about calling in a specialist (plumbing person) and having it examined by a professional? How is anyone supposed to judge this here without knowing what material it is, what exactly it looks like, etc? So I would get someone who knows their stuff and they can then tell you the best course of action.

So, that settles the matter ;)

You have a total hardness of 8.9 °dH. You absolutely do not need a water softening system!
I have 23 °dH and have reduced it to 7 °dH (can’t go lower, otherwise I would exceed the sodium levels in the water).

By the way, I work professionally with water treatment, so I know a bit more in this area.

And as already mentioned, there is no combination of softening and filtering. You don’t need that either. You have a main entrance filter and at your hardness level you don’t need softening. Just use the water as is for everything and drink it. I ONLY drink tap water. If I need water on the go, I fill a water bottle with tap water. People who buy overpriced water from the supermarket/beverage store are those who have too much money and like to lug things around and are ****** to the environment. (yes, I just can’t understand that ;) )

Regards
Specki

Ok, thanks so far.
Then I will think it over carefully again.
Regarding the softening system, I am concerned about the following points.
1. During the major renovation, I noticed the old water pipes. They looked accordingly inside...
2. My neighbor apparently has a softening system and his pipes look like new (they are currently remodeling)
3. I have a rain shower in the bathroom, which regularly gets lime scale deposits.

But if you say you can’t get below 7 °dH anyway, then the effort and costs are of course questionable!

Regarding drinking water treatment, I am still considering at least installing a system in the kitchen that additionally treats the water.
I haven’t researched what is available on the market yet, but my idea is to reduce nitrate and enrich minerals, if possible.

Best regards
Chris

These looked accordingly on the inside...

Made of what material? What does "accordingly" mean?

My neighbor apparently has a water softening system

Then he got involved with a good salesman (=scammer). With that hardness range, softening, as has already explained, is not a sensible investment.

3. I have a rain shower in the bathroom, which regularly gets limescale deposits

Evaporating water almost always leaves residues. It does not necessarily have anything to do with hardness-forming substances (Ca, Mg).

But if you say you can’t get below 7°dH anyway, then the effort and costs are naturally questionable!

If you want, you can get down to 0° with Lake Constance water, as there is hardly any sodium in the raw water. However, this is not sensible because hardness buffers the pH. pH changes can then in turn lead to corrosion problems, which you should hardly have anymore with current materials + Lake Constance water.

but my idea is the reduction of nitrate as well as the enrichment of minerals

Why? You have Lake Constance water, hardly any hardness, hardly any nitrate, hardly any sodium, top actually... and still want to hang something with a huge surface area (germ growth, biofouling) into the network, completely without any requirement.