Total Dissolved Solids in Water

Total dissolved solids (TDS) is the total weight of solids that are dissolved in a given volume of water, all these solids are primarily minerals, salts, and organic matter that can be a general indicator of water quality expressed in milligrams per liter (mg/l) or parts per million (ppm). The lower the TDS the more efficiently body cells get hydrated by the water you drink. The higher the TDS, the greater the probability of harmful contaminants that can pose health risks or hinder the absorption of water molecules on the cellular level. High TDS can also generally indicate hard water, which can cause scale build-up in pipes and appliances. Scale buildup reduces performance and adds system maintenance costs. The maximum TDS contaminant levels of secondary drinking water are 500mg/l or 500 PPM.

Many dissolved inorganic water contaminants or impurities exist as ions in solution, the most common of these ions are:

These electrically charged dissolved particles make ordinary natural water a good conductor of electricity. Conversely, pure water has a high electrical resistance, and resistance is frequently used as a measure of its purity, specific inorganic ions can be toxic.


Cations Anions
Calcium Ca+ + Bicarbonate HC09­
Magnesium Mg++ Chloride Cl
Sodium Na+ Sulfate SO,
Iron Fe+ + Nitrate NO,­
Manganese Mn+ + Carbonate CO,_ 

Water supplies can contain dissolved organic chemical contaminants which are usually pollutants that enter water as a result of man’s activities, such as insecticides, pesticides, and herbicides. These are usually chronically, rather than acutely, toxic to man and other species in extremely small amounts. Trihalomethanes are dissolved organic contaminants, such as chloroform, which are formed in extremely small amounts by the reaction of chlorine used to disinfect water, with humic and fulvic acids from soil erosion. Other organics can enter both surface and groundwater through waste dumping, such as trichloroethylene, tetrachlorethylene (TCEs), polychlorinated biphenyls (PCBs), dioxin, etc. Many of the organic contaminants are probably carcinogenic (cancer-producing). The organics do not necessarily exist in water in the form of dissolved ions.

TDS Water

Why should you measure TDS levels in your water?

If the TDS level exceeds 1,000 ppm (parts per million), it is considered unsuitable for human consumption. High TDS levels are an indicator of potential concern and should be checked before drinking. Even the best water purification systems on the market need to monitor TDS to ensure that filters and membranes are effectively removing unwanted particles from the water. The Secondary Drinking Water Ordinance mainly regulates pollutants in drinking water that impair the aesthetic quality of water. Some of these (chlorides, sulfates, copper, iron, manganese, zinc, and all dissolved solids) are ionized impurities. Colors and odors are pollutants that cause an unpleasant sensory reaction to water. You can also use pH to measure the acidity or alkaline intensity of your water supply. Corrosive refers to the ability of water to dissolve pipes and tanks. We are all influenced by the toxic chemicals in the air and the food we consume. It is important to make sure that the water source supplies pure water, as water is the only way to wash away these toxins. This is especially important for children. They are much more sensitive to contaminants, as their defense system has not yet been fully developed. The purer the water, the better your ability to purify your body, so drink!

Fitt Hydro-Systems provides water solutions by installing reverse osmosis water purifiers that stabilize TDS to the required levels approved by the World Health Organization.