TDS

(total dissolved solids) The amount of organic or inorganic material dissolved in water at the molecular level, small enough to pass through a 2 micron filtration screen. TDS can be approximated by measuring the electrical conductivity of the water using a conductivity meter. The higher the conductivity, the higher the concentration of dissolved solids. See also “conductivity”, “micromohs”, “RO water”, and “DI water”. Solids too large to pass through a 2 micron filter screen are considered TSS (total suspended solids).