Total Dissolved Solids (TDS)

What is TDS in Water?

Total dissolved solids (TDS) is the term used to describe the inorganic salts and small amounts of organic matter present in water. The principal constituents are usually calcium, magnesium, sodium, and potassium cations and carbonate, hydrogen carbonate, chloride, sulfate, and nitrate anions.

How is TDS Measured?

TDS is measured on a quantity scale, either in mg/L or, more commonly, in parts per million (ppm). If the TDS level is 335 ppm, this means that out of one-million parts of H2O, 335 of those parts are something else.

TDS Water Chart

Why should you measure total dissolved solids?

Total dissolved solids can affect your water quality, health, home plumbing systems, cooking, and cleaning. By measuring your water for TDS, you can better understand your water quality and how it affects your everyday life, allowing you to make an informed decision to solve your water quality problem and install the most effective filtration system for your home.

Taste & Smell 

Tap water with a high concentration of total dissolved solids (TDS) can have a bitter taste and unpleasant smell. The higher the concentration of total dissolved solids, the more bitter your water will be. A reverse osmosis system is recommended to improve the taste and smell of bitter tap water.

Health

High TDS water is not necessarily unhealthy to drink, but certain substances, such as lead and copper, are health hazards. A reverse osmosis system is recommended to filter heavy metals.

Filter Maintenance

Water filtration systems are a great solution to reduce total dissolved solids but are subject to normal wear and tear. Routine testing for TDS can provide assurance that your filter system is working properly and can alert you when maintenance is required.

Plumbing & Appliances

Water that contains high levels of dissolved calcium and magnesium is hard water and can result in high TDS levels. When calcium and magnesium salts dissolve, they collect in pipes and form scale buildup, resulting in costly pipe replacements and shortening your appliances' lives. A water softener is recommended to filter calcium and magnesium and can prevent scale buildup.

Cooking

Though not detrimental to your health at levels below 1000 ppm, cooking with elevated TDS water can change the taste of food. A carbon filter is an effective choice to remove chlorine from water.

Cleaning

If your dishes have water spots no matter how well you clean them, your clothes fade in the wash, and you have buildup in your sinks, your cleaning woes may be caused by high levels of total dissolved solids. A water softener can decrease the TDS level and make cleaning much more efficient.

Is low TDS water harmful?

No, low TDS water is not harmful. A low TDS level actually means you have high-quality water, but it may have a flat taste, as it is devoid of many minerals.

Please Note: This document is designed as a guide for household water treatment, not a recommendation. Before installing a household water treatment system, contact your local health department’s environmental health group for consultation.