How AQON PURE works in detail

AQON PURE is a solution for lime in tap water, which uses the so-called process of seed crystal formation through catalysis. On this page, you will learn the details of how this process works as well as the scientific principles.

The simple explanation: Lime learns to swim.

Lime in water consists primarily of the minerals calcium and magnesium. Instead of removing these valuable minerals calcium and magnesium (lime) from the water, AQON PURE reduces the accumulation behavior of lime in water. Lime is present in drinking water in dissolved form as calcium (Ca²⁺) and carbonate ions (CO₃^2-) before. When the water flows through AQON PURE, these ions touch the catalyst built into AQON PURE. The calcium and carbonate ions react on the catalytic surface and form small lime crystals (calcium carbonate CaCO₃). The resulting lime crystals serve as an attachment point for the remaining calcium and carbonate ions in the water. Instead of forming calcium deposits on surfaces such as pipes, the lime reacts with itself. The advantage: The mineral content of the water (the water hardness) is not reduced. The entire reaction takes place without the addition of chemical substances, as the catalyst is not used up. Put simply: Your lime learns to swim, is therefore less deposited and is simply washed out every time you draw water. This effectively reduces calcium deposits.

The scientific explanation:
seed crystal formation

In addition to catalytic seed crystal formation, there are other methods for seed crystal formation which have proven their effectiveness in practice [1]. The effectiveness of chemical-free water treatment has already been proven by renowned scientists [2, 3, 4] (including through catalytic action or through the action of electromagnetic fields [5]) and follows the following basic principles:

As already described above, calcium is present in drinking water in dissolved form as calcium (Ca²⁺) and carbonate ions (CO₃^2-) before. The catalytic action of certain metals [2, 4] influences the growth of calcium crystal nuclei and promotes early precipitation of the crystal nuclei in the form of aragonite. In the case of AQON PURE technology, this process is carried out through catalytic effects, in which special metals initiate the adsorption and so-called co-precipitation of crystal nuclei. [2] However, these catalyst metals are not consumed (not released into drinking water), but accelerate reactions that lead to calcium nucleation. In this process, the lime-carbonic acid balance is disturbed by components such as carbonate ions interacting with the metal interfaces. If the chemical equilibrium (e.g. excess of hydrogen carbonate ions) changes, the pH value is also affected, which increases, for example, “minimally”. [2, 6] The term “calcium hydrogen carbonate crystals” reflects the findings on how to control the nucleation of calcium crystals (we mean only metastable states in the nucleation process, which is difficult to represent to a general audience). The aim here is to choose terms that describe and emphasize the special role of hydrogen carbonate ions in the nucleation process of lime crystals (including influence on the structure of lime crystals). [6]

Through know-how in the design of water treatment plants, it is possible to bring the adsorbed, “immature” lime crystals back into solution under the action of shear forces, which we describe figuratively as “The lime learns to swim.” When the “immature” lime crystals agglomerate (i.e. build up) in a typical house installation, lime precipitates, but in an altered form. This is because the structure, known as crystal morphology, and size were converted by catalytic action into a state favorable for a “calcium deposit inhibiting” [2] Accordingly, under certain conditions, depending on temperature and flow rate, the “modified” lime adheres less strongly to interfaces of typical house installations, even without reducing the water hardness.

Picture: Functional diagram of AQON PURE lime protection technology [7]

Efficacy study

In addition to the scientific findings described above about the lime protection process for seed crystal formation, the effectiveness of the technology used in the AQON PURE system was independently tested in an 18-month study.

About the effectiveness study

The difference between
conventional
Water softening with
salt.

The biggest difference between seed crystal formation and conventional water softening with salt is that seed crystal formation does not release any salt or sodium into drinking water. A classic water softener with salt (sodium chloride) removes these minerals from the water and exchanges them for sodium. As a result, the mineral content (lime content) of tap water decreases and the sodium content rises. It's actually a contradiction, isn't it? At the supermarket, we also make sure that we buy water that is rich in the natural minerals calcium and magnesium (lime) and is low in sodium. So anyone who has previously relied on a classic softening system with salt to reduce calcium deposits has worsened their drinking water quality. At the same time, water softening systems with salt release large amounts of chloride through their waste water, which in turn is bad for the environment.

In addition, water softening systems are more expensive both to buy and to operate than lime protection systems. In addition, the ion exchange resin of a water softener with salt can increase the risk of contamination of drinking water, particularly during extended downtimes. For this reason, softening systems with salt must be serviced and cleaned annually by qualified personnel. In addition, it should not be forgotten that water softening systems with salt must be regularly refilled with regenerating salt (approx. 100 kg per year for a single-family house with 4 people).

What works better?
Water softening with
Salt or lime protection?

It is difficult to make a final assessment of this issue. Comparative tests of both methods have also been lacking so far. Because even though a water softening system with salt reduces the lime content (the water hardness) of tap water, these systems do not provide lime-free water. For reasons of corrosion, a water softening system with salt always leaves a so-called residual water hardness (residual amount of lime) in the water.

Both this residual water hardness of a softening system with salt and the modified lime resulting from the process of seed crystal formation lead to traces of lime on surfaces after a certain period of time when water evaporates, for example. Kitchen appliances such as kettles also need to be descaled less frequently, but still need to be descale after a certain period of time. Probably a bit rarer when using a water softener with salt. In contrast, there are the advantages of a lime protection system based on the principle of seed crystal formation in terms of acquisition costs, operating costs, drinking water quality and environmental friendliness.

In summary: Both processes reduce calcium deposits in the house and make living with lime in your own home more pleasant. However, cleaning is not spared in both cases, but it is easier.