Total Dissolved Solids (TDS) are the total amount of mobile charged ions, including contaminants, salts or metals dissolved in a given volume of water, expressed in units of mg per unit volume of water (mg/L), also referred to as parts per million (ppm). TDS is directly related to the purity of water and the quality of our water purification systems and affects everything that consumes, lives in, or uses water, whether organic or inorganic. Basically, it measures EVERYTHING in your water, that's not water.
The level of TDS indicates how clean your water is, see below:
From our testing, the average TDS level found within the West Midlands is between 200 and 350.
This is just passed the marginally acceptable levels set by the U.S. EPA. This is because the West Midlands is known that have hard water, which has levels of artificial fluoride, calcium, magnesium and chlorine as well other possible contaminants.