What is TDS and does it matter?

TDS stands for Total Dissolved Solids. It measures the combined amount of dissolved substances in water, including minerals, salts, and metals.
TDS affects water composition, but a high TDS reading does not automatically mean water is unsafe.

TDS may include:

• Calcium

• Magnesium

• Sodium

• Potassium

• Chlorides

• Sulphates

• Nitrates

• Dissolved metals

These substances are fully dissolved in water and cannot be removed by standard sediment filtration.

TDS is typically measured in:

• mg/L (milligrams per litre)

• ppm (parts per million)

Higher numbers indicate a higher concentration of dissolved solids.

Not necessarily.
Some dissolved minerals, such as calcium and magnesium, are naturally occurring and safe at typical levels.

However, very high TDS may indicate:

• Salinity

• Brackish water

• High mineral content

• Dissolved contaminants

A laboratory report is required to determine what the dissolved solids actually consist of.

High TDS may affect:

• Taste

• Scaling potential

• Appliance lifespan

• Plumbing longevity

It does not automatically indicate bacterial contamination.

Standard filtration methods such as:

• Ultrafiltration

• Activated carbon

• UV sterilisation

do not remove dissolved solids.

TDS reduction typically requires:

• Reverse osmosis

• Distillation

• Specialised ion-exchange processes

TDS becomes important when:

• Water tastes noticeably salty or metallic

• Lab reports show elevated dissolved contaminants

• Brackish or coastal groundwater is used

• Salinity levels are high

In such cases, reverse osmosis may be recommended.

TDS is different from:

• Hardness (calcium and magnesium concentration)

• Microbiological contamination (bacteria and pathogens)

Each issue requires a different treatment approach.