Water filter for the whole house or just for the kitchen?

Home water filter or kitchen filter?

Additional domestic water filters behind the house's plumbing are particularly useful for removing limescale. However, a Carbonit domestic filter system can also remove medication residues and pesticides. To ensure proper functionality, however, they must be properly installed and maintained. But what can these filter systems really do? What regulations must be observed? Here are a few answers.
Many people are familiar with the problem: Limescale builds up in the kettle, limescale traces appear in the bathroom, and detergent often requires a high dosage. Smaller filter systems for a single faucet in the house are of little use. Therefore, there are options for centrally filtering tap water: Additional filters or a descaling system can be installed directly behind the water filter on the house's plumbing.
Are there any regulations that must be observed?

At first glance, the question of the purpose of a domestic water filter is easy to answer: The legislator considers the installation of a central filter system at the house connection to be necessary and stipulates its installation directly behind the water meter, at least in the case of metal pipes, within the framework of DIN standard EN 806.

Installation of plastic pipes is expressly recommended. This regulation is based on the potential for contamination of drinking water on its journey from the waterworks to the household connection. The kilometer-long pipeline network in Berlin, for example, is partly more than 100 years old. A lot of contaminants can enter the water along the way.

However, the systems used in this context primarily serve to filter sediment and rust and do not remove other undesirable substances such as limescale from the water.

For common domestic water filters specified by DIN standards, a distinction is made between backwashable and non-backwashable versions. Here, we will focus on larger domestic water filter systems.
What is the difference between water filters in household appliances and drinking water filter systems on the kitchen table?

If you want to further remove limescale from your water, you can use additional filter systems. These can be divided into filter systems that are installed only at individual water connections in the house, such as in the kitchen, and centralized filter systems. These are installed after the house's plumbing to filter all the water in the house. Once such a system is installed, you will receive filtered water throughout your entire house—from the kitchen to the toilet flush. Water can be filtered much better and more intensively at a single tap in the kitchen. This significantly reduces not only limescale but also pollutants such as pharmaceutical residues, pesticides, and heavy metals.
What benefits do special household water filters offer?

The most common reason for choosing central water treatment is an undesirably high limescale content in the water, which manifests itself unpleasantly in the form of deposits on various household appliances and causes them to wear out quickly. In private households, a domestic water filter based on ion exchange resins can be used to reliably combat limescale. Here, the limescale-forming calcium ions and magnesium ions are exchanged for sodium ions. The result is no or significantly fewer limescale deposits throughout the house. However, an elevated sodium concentration (table salt) could be unfavorable for patients with high blood pressure. These patients should consult their doctor before installation.

Other possible uses for centrally connected water filters include the removal of chlorine, organic particles, drug residues, heavy metals, and pesticides. Special filter systems remove these substances from the water, ensuring appropriately filtered water throughout your home. Dissolved limescale, on the other hand, remains in the water, but is easier to remove from surfaces due to the absence of hardness-forming substances than without filtration at all.

Disadvantages

All water is filtered, and you have to pay for it. This includes the flush water in the toilet, which is filtered unnecessarily. This results in relatively high maintenance and high installation costs.

Advantages

With limescale filters, limescale deposits are eliminated throughout the house. Plumbing in the house is protected.

Conclusion

Whether a domestic water filter in the form of a central water treatment system against limescale makes sense depends on how important the central removal of limescale is to you.

A domestic water system that removes all other contaminants doesn't seem sensible to us due to the high cost. Instead, we recommend a reverse osmosis system or an activated carbon filter at the water tap in the kitchen. This will provide you with ultrapure water for cooking and drinking, something unobtainable with a central water treatment system.
Tip for tea drinkers: The Bellima water compartments for tea drinkers are a simple, inexpensive but good option.