In general, "limescale in water" refers to the proportion of dissolved salts/minerals that contribute to water hardness: calcium and magnesium. These exist as calcium and magnesium carbonate, and their total amount determines the chemical hardness, the degree of hardness, of the water. Together, they normally constitute by far the largest proportion of dissolved substances. Furthermore, the limescale also exists in undissolved form, in small lumps, so to speak.

When water is heated, limescale – both dissolved and undissolved – precipitates and settles, particularly at the heat source, such as heating elements in washing machines and boilers. This precipitation forms a hard layer, known as limestone. On faucets and everywhere else, limescale forms similar layers as the water evaporates, sometimes more, sometimes less, depending on the degree of hardness and physical composition.

In tea, the "hardness" forms an unsightly bitter deposit that floats on the surface. In drinking water, limescale is often sensitively detectable as a "dull" or "hard" aftertaste.

Problem solving

The undissolved limescale can be easily removed with an activated carbon block filter or a combined activated carbon/microfilter. The remaining dissolved limescale deposits are soft and do not form encrustations. Even tea drinkers sometimes find this effect sufficient, eliminating the need for chemical descaling or similar treatments.

A special product was developed specifically for tea drinkers. It removes the unsightly bitter residue that floats on the surface and also softens the water. The tea tastes significantly better. ( Bellima Water Fan )

Ion exchanger (chemical softening)

Within an exchanger cartridge, calcium and magnesium are removed from the drinking water through a chemical process using synthetic resins and replaced with sodium. The "used" synthetic resins must be regenerated with salts at regular intervals.

+ The water is softened, limescale deposits are prevented
- Regular regeneration with special salt; regular inspection (every 2 months) and maintenance (every 12 months) necessary
- No corrosion-inhibiting effect
- Mixing with untreated water (“blending”)

Dosing systems (chemical hardness stabilization)

Dosing systems add phosphates, silicates, alkalizing substances, and/or a combination product to the drinking water depending on the flow rate and the determined raw water quality. These substances can stabilize the hardness-forming substances. They can also support the formation of a mineral corrosion protection layer.

+ The hardness-forming substances are stabilized; limescale deposits are prevented
+ Supports the formation of a mineral protective layer against corrosion
- Regular replacement of the dosing agent containers and inspection or maintenance (every 6 months) necessary
- Over- or underdosing in case of changing water quality

Permanent magnetic processes (physical hardness stabilization)

Using one or more permanent magnets installed in or around the pipes, a magnetic force field is generated that stabilizes the hardness-forming substances by exciting crystal nuclei. Various mechanisms (e.g., water accelerators) are used to enhance the force field.

+ Relatively inexpensive; maintenance-free
- No convincing stabilization of the hardness-forming substances
- Efficiency levels vary greatly

Electromagnetic processes (physical hardness stabilization)

Using individually dimensioned toroidal coils, an electric current is applied to generate a magnetic force field. This field stimulates the minerals to bond with each other. Some manufacturers reverse the polarity of the magnetic currents at regular intervals using an electromagnetic controller to repel any adhering substances (e.g., iron).

+ Partially good stabilization of hardness-forming elements; maintenance-free
- By electric current: running costs and unwanted electromagnetic vibrations
- Efficiency levels vary

Current pulse process (physical hardness stabilization)

In these processes, current pulses are applied to electrodes immersed in water. The current density causes microcrystals to form at the cathode, which are carried along by the water due to the polarity reversal of the alternating current. These crystals do not deposit on the inner walls of the pipes; they are washed out with the water.

+ Relatively good stabilization of the hardness formers
- By electric current: running costs and unwanted electromagnetic vibrations
- ZT inspection / cleaning of the electrodes required

Biomagnetic treatment (physical hardness stabilization)

influence the water from the outside in such a way that it "releases" the dissolved lime from the usual hydration shells, allowing "pre-crystallization" to occur spontaneously. Even encrusted lime and rust on the inside of the pipes can be dissolved again during this process. The temperature at which the lime precipitates is increased, sometimes even beyond the boiling point. This type of lime treatment is relatively inexpensive and generally requires no maintenance, thus also no follow-up costs.

+ relatively inexpensive, easy to install
- Efficiency levels vary

Catalytic processes (heterogeneous catalysis)

The water flows at an accelerated rate into the bed of spherical granules, stirring the granules and keeping them suspended. Contact between the lime components dissolved in the water and the surface of the granules promotes optimal growth of lime crystals. Once they reach a certain size, these "seed crystals" are detached by the water flow and washed away.

The crystals do not grow beyond a size of approximately 30 µm and remain suspended in the water without chemically altering it. They no longer adhere stubbornly to surfaces. This provides the best possible protection for high-quality equipment and simultaneously creates a natural foundation for optimal aroma development.

+ The hardness formers are stabilized quite reliably
+ Solid limescale deposits are prevented
+ No chemicals, no electricity
+ the installation is low-maintenance
- Although the granulate material doesn't wear out, it can become ineffective due to contamination. Replacing the special granulate isn't particularly inexpensive.

Which limescale treatment is the right one?

The important factors for choosing a solution are first the purpose, then the possible locations of use and, of course, the price-benefit and price-performance ratio:

For softer water, especially in the kitchen of a rental apartment, a good filter, such as one from Carbonit, or a reverse osmosis drinking water system is often sufficient. An entire rental apartment is usually supplied via several risers that are inaccessible to tenants. Here, terminal devices are the only sensible solution...

For softer water in the entire single-family or two-family house, the biomagnetic (relatively inexpensive) or the catalytic limescale converters (best effect) often perform best (taking the above-mentioned aspects into account).

In large apartment buildings and commercial facilities, the focus is on the purpose and thus the actual measurable improvement of the problem (machinery/heating/drinking water/pipes/water use...).