TDS - Total Dissolved Solids An expression for the substances contained in a liquid which are present in a molecular, ionized or micro-granular suspended form. The operational definition is that the solids must be small enough to pass through a two microns filter. The term is used as an indirect reflection of water salinity. The term is also known as total filterable residue. (read more)

  Turbidity The cloudiness or haziness of a fluid caused by suspended solids particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality and it is measured by the amount of Light transmission through a water sample.(read more)