The media within the Black Berkey® Purification Elements is not designed to remove beneficial (ionic) minerals from your water supply. These kinds of minerals can be reduced if they are in high concentration, but some will still be allowed through. We have not done any testing for the removal rate of ionic minerals, as they are not supposed to be completely removed to begin with. There are no water filtration companies on the market that publish a test of that nature.
Electrolytes are compounds such as sodium, potassium, calcium, etc. They help perform the functions of muscle contraction and heartbeat among other various bodily tasks. Many electrolytes also fall under the category of beneficial minerals, so we do not have specific test results for electrolytes. We do have test results for one particular electrolyte, chloride, which is reduced by the Black Berkey® Purification Elements in excess of 99.6%. If you would like to add electrolytes to your water, we recommend using electrolyte additives in the lower chamber of your Berkey® System.