As many people have hard water I'm quite often asked if the Black Berkey filters also soften water. Hard water is the presence of calcium carbonate in your drinking water which then appears as limescale caking on the element in your kettle for instance.
The Black Berkey filters do not soften or decalcify water. One of the main advantages of the Black Berkey filters is that the beneficial minerals present in the water are not removed as is the case with reverse osmosis or distillation. For a further discussion of this issue please see Berkey, Reverse Osmosis and Distillation Compared for a detailed description of the pros and cons of reverse osmosis and Berkey water filter systems.
You may find that the limescale build-up in your kettle is less or disappears completely using Berkey purified water. For instance, you may see white particles floating in the bottom of your kettle instead of building up on the element. This is because the ionic charge of the minerals changes by passing through the Black Berkey filters, the water becomes more alkaline and is then not able to hold all the minerals in solution, these minerals may then precipitate out and float in the bottom of the kettle. Every once in a while, you can rinse out the kettle and your hard water issue is resolved. You may also find a gritty layer building up and adhering to the sides of the lower chamber. Cleaning out the lower chamber with a mild vinegar solution will get rid of this build-up.
If you have a sightglass spigot the sightglass may also become cloudy after a year or so due to calcium carbonate build-up in the glass tube. Empty the lower chamber of your Berkey and unscrew the aluminium casing from the tap, being very careful that the glass tube does not fall out and break. Place the glass tube in pure white vinegar, and leave it there until the calcium carbonate dissolves and the glass is again clear, then rinse off and re-attach to the tap.