What does resistivity/conductivity mean?
The majority of impurities in potable water are in the form of disassociated ionized mineral salts such as NaCl and CaCO3. Because such ions by definition carry an electrical charge, their presence is directly related to the ability of the water to conduct electricity, or resistivity. Hence, resistivity (and its reciprocal conductivity) are the best parameters by which to gauge the purity of water. Resistivity is a measure in ohm-cm and its reciprocal conductivity is measured in mhos-cm or siemens. It is important to realize that resistivity/conductivity is a measure of only ionic impurities and is not affected by particulates, bacteria, or other organic contamination. We usually use a 10k light to indicate when the filter needs to be regenerated.
