TDS represents the combined total of all organic and inorganic substances found in drinking water. TDS present in water is one of the leading causes of particles and sediments in drinking water, which give water its colour, odour, flavour and can be a general indicator of water quality. The TDS levels are measured by a TDS meter. This small device is used to assess how many particles are present in drinking water.

Organic substances present in drinking water may include:

• Algae

• Bacteria

• Fungi

• Hair

• Pesticides

• Herbicides

• Fertilizers

• Disinfectants

• Pharmaceuticals

Inorganic substances present in drinking water may include:

• Arsenic

• Lead

• Mercury

• Chlorine

• Sodium

• Calcium

• Potassium

• Magnesium

• Fluoride

Total Dissolved Solids are most often measured in parts per million (ppm) or milligrams per litre of water (mg/L). The normal TDS level ranges from 50 ppm to 150 ppm, which is good for human health. The increased amount of dissolved solids can also have technical effects such as TDS can produce hard water, which leaves deposits and films on fixtures and can corrode the insides of hot water pipes and boilers.

Water with high levels of TDS above 500 ppm is considered unfit for human consumption. The high levels of TDS are caused due to the presence of potassium, chloride, sodium and toxic ions in larger amounts. It is undesirable to drink as it may taste salty, metallic or bitter.

The low levels of TDS, 100 ppm may have a flat or diluted taste to them and be unpalatable.

The high level of TDS means it is unfit for consumption and can cause nausea, rashes, vomiting, dizziness, hair fall, etc. Drinking water with an elevated amount of TDS for longer periods will expose the body to various chemicals and toxins and may cause chronic health conditions like kidney failure, nervous system disorders, weakened immunity and may also cause birth defects in the new-born.