Occasionally use undiluted Kalkosan to clean the shower doors. Now experienced issues with the grout dissolving. Could this be related to Kalkosan?
Yes, it contains phosphoric acid and citric acid so it dissolves the grout.
My misstake. Do you think it can solve the kakelfix issue as well? The klinkers have also started coming loose from the floor.
Virtually all products that dissolve limescale contain more or less strong acids and attack tile joints because the grout in the tile joint contains more or less a large part of cement, which in turn is burned and slaked lime. - if it starts to bubble and fizz, it's a sign that it's dissolving the grout.
If you want to remove discolorations and other deposits on surfaces that are not limescale, you can try chlorine mousse or an equivalent product from another manufacturer, as it is strongly alkaline and dissolves organic growths like algae and various molds while disinfecting. Strong alkaline solutions do not attack the tile joint but instead, they can attack aluminum parts, trims, and others if there are such things in the shower area.
---
The best way to maintain shower walls and shower enclosures free from limescale spots and other stains is to wipe down the walls and floors with a window squeegee/floor squeegee after every shower of all family members if it's not directly after one another. After some time, you'll get the hang of it, and it doesn't need to be very precise or take much time - if you miss a section one time, it will be addressed the next. In short, there shouldn't be much steam and droplets left on the walls and floors when you're done.
If you neglect this, you'll begin to see signs of dried water spots after just a few showers, especially if you have slightly harder water. Some of the spots are difficult to remove because they are not limescale but gypsum and soap scum - particularly the latter if regular soap is used in the shower - and practically nothing will dissolve them regardless of household chemicals and must be worn down layer by layer, such as with the rubber squeegee. Soap scum can be more easily removed if you use a steam cleaner and simply heat the surface thoroughly so that the fats they consist of melt and become easier to remove.
If you want to remove discolorations and other deposits on surfaces that are not limescale, you can try chlorine mousse or an equivalent product from another manufacturer, as it is strongly alkaline and dissolves organic growths like algae and various molds while disinfecting. Strong alkaline solutions do not attack the tile joint but instead, they can attack aluminum parts, trims, and others if there are such things in the shower area.
---
The best way to maintain shower walls and shower enclosures free from limescale spots and other stains is to wipe down the walls and floors with a window squeegee/floor squeegee after every shower of all family members if it's not directly after one another. After some time, you'll get the hang of it, and it doesn't need to be very precise or take much time - if you miss a section one time, it will be addressed the next. In short, there shouldn't be much steam and droplets left on the walls and floors when you're done.
If you neglect this, you'll begin to see signs of dried water spots after just a few showers, especially if you have slightly harder water. Some of the spots are difficult to remove because they are not limescale but gypsum and soap scum - particularly the latter if regular soap is used in the shower - and practically nothing will dissolve them regardless of household chemicals and must be worn down layer by layer, such as with the rubber squeegee. Soap scum can be more easily removed if you use a steam cleaner and simply heat the surface thoroughly so that the fats they consist of melt and become easier to remove.
Theoretically, if your kalksan goes down under the tile, it will affect all cement-based materials, but it would likely take an extreme amount over a longer time for this to be the main reason that tiles come loose if the tiles had full coverage before. Possible yes, likely (as the main reason) not really.