Domestic Water Filtration


Additional domestic water filters behind the domestic installation with the prescribed filter system achieve good results, especially when removing limescale. However, they must be correctly installed and maintained in order to guarantee their functionality. But what do these systems really do? Which regulations have to be observed? Below are the answers which you could learn more from the team at Drink Filtered.

Many people know the problem

If lime deposits regularly in the kettle, corresponding annoyances can also be expected in the bathroom and the detergent usually has to be dosed in high doses to achieve the desired effect. Smaller filter systems for a single tap in the house quickly reach their limits. Less well known, however, are the possibilities of centrally treating tap water: Additional filters can be installed directly behind the prescribed water filter on the house installation.

What are the regulations for domestic water filters?

At first glance, the question of the usefulness of a domestic water filter seems easy to answer: the legislator considers the installation of a central filter system at the domestic connection necessary and makes the installation directly behind the water meter mandatory, at least for metallic pipes within the scope of DIN standard EN 806.

Installation is expressly recommended for plastic pipes. The reason for this regulation results from the possible contamination of the drinking water, which can occur from the waterworks to the house connection. Sand and rust particles, for example, which are removed by the filters, can enter the water by passing them through the pipe network. All filters used must bear an official seal of approval.

What is the difference between water filters in building services and drinking water filter systems?

If, on the other hand, you want to treat your water additionally and, for example, take action against the undesirable limescale deposits mentioned above, you can use additional filter systems for this purpose. A basic distinction can be made between filter systems that are only installed at individual water connections in the house, often in the kitchen, and central filter systems that are installed after the house installation and filter all the water in the house.

If a second category system is installed, you will receive filtered water throughout the house – from the kitchen to the toilet flush. The first category, on the other hand, aims to remove pollutants such as pharmaceutical residues and toxic heavy metals.

What services do special house water filters offer?

The most common reason for choosing a central water treatment system is an undesirable high lime content in the water, which makes itself felt unpleasantly on deposits on various household appliances and promotes their rapid wear. The removal of the alkaline earth ions calcium and magnesium in the water, which are not harmful to the body and are responsible for limescale formation, is not considered absolutely necessary by the authorities and is therefore not carried out in waterworks.

How do filters for removing limescale work?

The most commonly used water softening method is based on the so-called ion exchange. When water is treated with this method, calcium and magnesium in the water are replaced by sodium.

As a result, the sodium content of the water increases, which probably has no effect on the taste, but can lead to the prescribed limit value for sodium (200mg/l according to the Drinking Water Ordinance) being exceeded. Because per exchanged degree of hardness an ion exchanger releases about 8mg sodium per litre to the water . The biggest disadvantage of a water softening system based on ion exchange is the continuous control and maintenance. Depending on the composition of the water, the exchange granulate can exhaust faster or slower, so that the next point in time for maintenance is difficult to estimate.

What are the advantages of additional filtration?

The advantages of using an additional domestic water filter always depend on the model used. If you have to deal with limescale deposits in several rooms, typically in the kitchen and bathroom, central limescale filtration seems to make sense. Even if you attach particular importance to exceptionally pure water for drinking, cooking, showering and washing, it is worth considering the purchase of a suitable filter. With a suitable lime filter you can protect your pipes and tubes on a long-term basis.

Which disadvantages have to be considered?

When installing a house entrance filter, it is important to remember that all the water in the household is actually treated additionally. Whether this is necessary, for example, for flushing the toilet, is questionable. In addition, depending on the water filter, the rather high acquisition costs and, last but not least, the necessary installation and maintenance costs must also be taken into consideration. Domestic water filters must be installed by a specialist, checked regularly and maintained at regular intervals in order not to accidentally become a germ catapult.

With a decalcification system, not only is maintenance, as already mentioned, time-consuming and important, but the fact that the water becomes aggressive due to the removal of calcium carbonate (the pH value becomes slightly acidic) is also a property that should not be underestimated. This is due to the lime/carbonic acid ratio which is no longer in equilibrium. The treated water can therefore attack the line pipes over time (especially galvanised or plastic pipes) and the quality as drinking water is also reduced.