Understanding TDS: What Total Dissolved Solids Reveal About Drinking Water

Most consumers know how to read a nutrition label, but fewer know what to look for when evaluating the water they drink every day. NWB Finland Oy, the Finnish company behind AINA Natural Water, says one useful measurement consumers may encounter is Total Dissolved Solids, commonly known as TDS.

TDS measures the concentration of dissolved substances in water. These can include naturally occurring minerals and salts such as calcium, magnesium, sodium, potassium, bicarbonates, chlorides and sulfates. The amount and composition can vary significantly depending on where water originates and what it encounters along the way.

"TDS gives consumers another way to understand the characteristics of the water they're drinking," said Marita Weiman, Quality Assurance Manager at NWB Finland Oy. "Water may look the same in a glass, but its mineral composition and taste profile can be very different depending on its source."

TDS is typically expressed in milligrams per liter (mg/L). A higher number generally indicates that more dissolved substances are present in the water, while a lower number indicates fewer dissolved substances. TDS alone, however, should not be interpreted as a measure of whether water is healthy or safe. The U.S. Environmental Protection Agency lists TDS under its National Secondary Drinking Water Regulations, which address aesthetic characteristics such as taste, odor and appearance rather than establishing TDS as a health-based standard.

Taste is where TDS becomes particularly interesting for consumers. The World Health Organization has noted that dissolved solids can affect the taste of drinking water and that the types and concentrations of minerals present can influence the drinking experience.

"Consumers often describe water as soft, crisp, mineral, salty or even metallic without necessarily knowing why," Weiman said. "Mineral composition is one of the factors that can contribute to those differences. That's why we believe understanding TDS can help consumers become more informed about something they consume every day."

AINA Natural Water provides an example of a naturally low-TDS water. It originates in the Pudasjärvi region of Northern Finland, where groundwater is naturally filtered through layers of soil, sand and rock before being mechanically filtered and packaged. AINA Natural Water contains approximately 32 mg/L of Total Dissolved Solids. Its naturally low mineral content contributes to the soft, neutral taste and clean finish that NWB Finland Oy considers central to the AINA drinking experience.

Rather than adding minerals or altering the water to create a particular taste profile, the company's approach is centered on preserving the natural characteristics of the groundwater source. "We want AINA to taste like what it is: natural water from Northern Finland," Weiman said. "The low TDS is not something we've engineered into the water. It's one of the measurable characteristics of the source."

As NWB Finland Oy continues its expansion into the United States, the company believes education can play an important role in helping consumers look beyond packaging and marketing terminology when choosing drinking water. "People are becoming much more interested in where their food and beverages come from and what they contain," Weiman said. "Water should be no different. Understanding measurements like TDS gives consumers one more piece of information they can use when comparing the choices available to them."

AINA Natural Water is preparing to become available to U.S. consumers through OneLavi.com as NWB Finland Oy continues building its presence in the American market. For more information, visit ainanaturalwater.fi and nwb.fi.