Valeacell ballpoint pen

Impurities in the water before filtering: If the water already contained impurities that were not completely removed by the activated charcoal filter, these impurities may have been concentrated during the boiling process, resulting in residues.

Overloading the filter: If the activated charcoal filter is overloaded, it may not be able to remove all impurities effectively. This could result in certain impurities, such as limescale, remaining in the water in higher concentrations and building up during cooking.

Insufficient filter maintenance: Activated charcoal filters must be regularly maintained and replaced to maintain their effectiveness. If the filter has not been properly maintained, its performance may decrease over time, resulting in insufficient removal of impurities.

Boiling process: In some cases, residues can be created by the boiling process itself, especially if the water has been heavily evaporated and mineral residues remain.

Mineralize filter: Filters out only contaminants - important minerals remain in the water

It is important to note that activated carbon filters cannot remove 100% of all contaminants, and effectiveness may vary depending on the specific contaminants in the water. In some cases, it may therefore be advisable to consider additional water treatment methods