Solids material that totally dissolves in water and can be removed by means of filtration. There are many elements within water that can be considered as dissolved solids such as metals, salts, anions, cations and minerals which are dissolved in water. Water treatment experts are routinely exposed to water sources that contain high amounts of total dissolved solids (TDS), which represent the total amount of dissolved solids in the water. TDS are made up of chlorides, sodium, magnesium, calcium, potassium, sulfates and inorganic salts, including a lesser amount of organic substances that also dissolve in water.