[CarstenW]

I watched a video on decalcifying today, and the recommendation he made was to do it every 20g of calcium, per liter of boiler. The Elizabeth has 0,6+0,3l boilers, so a total of 0,9l, which means for every 18g of calcium. For him that was every 100l of water through the machine, but it depends on the hardness of the water you are putting through. His hardness was 20. Scale accordingly. I can post a link to the video if interesting, but it is in German, on YouTube. The subtitles can be set to auto-translate to English.