What Is TDS in Water & Why Should You Measure It?

Water is often referred to as the universal solvent due to its capacity to dissolve and absorb molecules from a wide range of materials. The concentration of dissolved particles in water is known as the Total Dissolved Solids (TDS) level. Knowing your water's TDS level-as well as the specific dissolved solids it contains-helps provide a clear understanding of its overall quality. In this article, you'll learn about the various types of dissolved solids, how to measure them, and effective ways to reduce TDS in your water.

 

What is TDS in water?

Total dissolved solids (TDS) represent the concentration of organic and inorganic substances-including metals, minerals, salts, and ions-dissolved within a given volume of water. In essence, TDS measures all components present in water other than H₂O molecules. When water comes into contact with soluble substances, particles from these materials are incorporated into the water, forming TDS. These dissolved solids can originate from diverse sources such as natural springs, chemicals added during municipal water treatment, runoff from urban or agricultural areas, and household plumbing systems.

 

Where do TDS come from?

Total dissolved solids (TDS) originate from a variety of natural and human-made sources. Natural contributors include springs, lakes, rivers, vegetation, and soil. For instance, as groundwater moves through rock formations in springs, it dissolves minerals like calcium, magnesium, and potassium.

 

Human activities also significantly contribute to TDS levels in water. Pesticides and herbicides may enter water systems through agricultural runoff, lead can leach from aging pipes, and chlorine is often introduced during water treatment processes. In some cases, dissolved solids are intentionally added to water in the form of mineral supplements.

 

What is the best TDS level for drinking water?

According to the EPA's secondary drinking water standards, the recommended maximum level of Total Dissolved Solids (TDS) in drinking water is 500 parts per million (ppm). Measurements exceeding 1000 ppm are considered unsafe, and if TDS levels rise above 2000 ppm, many filtration systems may no longer be effective at reducing contaminants to acceptable levels.

 

What is a TDS meter?

Using a TDS meter is the easiest method to measure the total dissolved solids in water. For instance, a reading of 100 ppm means that out of one million particles, 100 are dissolved ions-indicating a low TDS level.

Why should you measure total dissolved solids?

Taste and smell

Tap water containing high levels of total dissolved solids (TDS) often has a bitter taste and unpleasant odor. The greater the TDS concentration, the more pronounced the bitterness becomes. To enhance both the flavor and smell of such water, using a reverse osmosis system or a ceramic water filter is recommended.

 

Health

Water with high TDS is not necessarily harmful to drink, but specific contaminants such as lead and copper can pose serious health risks. For instance, lead exposure may lead to brain and nervous system damage, while high copper levels can cause nausea and other symptoms. To effectively remove heavy metals like these, using a reverse osmosis system or a water distiller is recommended.

 

Filter maintenance

Water filtration systems effectively reduce total dissolved solids (TDS), but like any equipment, they undergo gradual wear over time. Regular TDS testing helps verify that your filtration system is functioning correctly and signals when maintenance or component replacement is needed.