What are Total Dissolved Solids (TDS) and How to Reduce Them?

August 10, 2020

Since water is one of the essential components of everyday life, ensuring that the drinking water you consume is free from all contaminants and hazardous chemicals is important. In a normal filtration process, large substances are filtered out quickly while finer particles remain dissolved in the water, which is known as TDS (total dissolved solids).

Dissolved minerals in water can cause serious health problems, plus it also alters the taste of the drinking water. Thus, let’s look at what is TDS in water, how to measure it, and the effective ways to reduce TDS level in water.

1] What are Total Dissolved Solids (TDS) in Water?


TDS in water is a combination of both organic substances (from natural sources) such as minerals & ions and inorganic substances (man-made) like pesticides, fertilizers, road salts, chemicals etc. As a solvent, water absorbs particles and impurities easily as it passes through different surfaces, rocks, soil, and pipes. These dissolved solids remain at varying levels of concentration in the water.

TDS level under 500 PPM is safe for human consumption and generally speaking, groundwater has a higher TDS than surface water.

2] Why Should You Measure TDS in Water?


The primary reason to measure the TDS in water is to discern the overall quality of water. High TDS levels in water indicate the presence of chemicals & contaminants, which may be harmful to health. Thus, regular checking of the TDS level in water is vital. Other reasons include:

  • Altered Taste: Water with high TDS level can have a salty, bitter or sulfuric taste.
  • Health Hazards: High levels of dissolved substances like copper, fluorides, arsenic and lead in water can also affect your health over the long term.
  • Plumbing and Appliances: High levels of dissolved calcium and magnesium salts can form scale and build-up in pipes and reduce the lifespan of appliances.
  • Cooking: While TDS levels below 500 ppm is not harmful, high TDS level in water can alter the taste of the food or beverage.
  • Cleaning: From fading of colours from clothes to water spots on utensils to build-up in sinks & faucets, high TDS level in water can cause a series of problems.
  • Water Purifier Maintenance: A high level of TDS can affect the water purification systems, so regular checking is needed to ensure that it is working optimally.

3] How Much TDS is Safe For Drinking Water?


If the TDS in drinking water is more than 500mg/L, then it is considered to be high, and it is recommended that it be treated before consumption. Also, while low TDS in water may indicate better water quality, very low level of TDS may lead to a flat or slightly bitter taste. So what should be the normal TDS in water or what is the permissible range of TDS in drinking water?

The TDS chart below explains this.

TDS Levels in mg/litre Permissible Range
Less than 300 Excellent range for drinking water
300-500 Good range
600-900 Fair range
900-1200 Poor range
Above 1200 Unacceptable range

For acceptability/ non-acceptability factor, you can check out the table below.

TDS Levels in mg/litre Acceptability/ non-acceptability factors
Less than 50 Low TDS indicates lack of natural nutrients and minerals. So it is not acceptable.
50-150 This is an acceptable range (80-150).
150-250 This is the healthiest range.
250-500 This is acceptable.
500-900 This needs RO water purifier to reduce the TDS level.
900-2000 This needs RO water purifier to reduce the TDS level.
Above 2000 Not safe for consumption.

4] How to Reduce TDS in Water - Different Ways


Water is a scarce commodity, especially in India. After measuring the TDS in drinking water if you find that the level is unacceptable, then you can try out the below ways to reduce TDS levels.

  • Reverse Osmosis (RO) System
  • RO systems make use of a semi-permeable membrane to eliminate total dissolved solids from water including heavy metals, toxic impurities, arsenic and others. It is one of the most cost-effective ways to reduce TDS in water, and if the TDS level in water is above 500 ppm, then this is the ideal solution to treat it.

  • Distillation
  • In this process, contaminants are removed through evaporation. Water is boiled to produce vapours, which rises to the cool surface and then condenses back into the liquid form. While dissolved salts, which cannot vaporise, settles at the bottom, providing you with distilled water. This process, however, is time-consuming, inconvenient and not very effective.

  • Deionisation (DI) System
  • In this process, total dissolved solids are removed through ion exchange. The water passes through a membrane with positive & negative electrodes, wherein positive ions detach themselves from the water and move towards the negative electrode, resulting in de-ionized water. Here, however, water is first passed through a RO system before it goes through the process of de-ionisation.

5] Which Method is Preferred?

From the above you can see that using a RO purifier may be the best way to reduce the TDS in drinking water. So, now that you have a general understanding of what is TDS in water, the next step includes finding the right water purifier for your needs. The different types of water purifiers include:

  • Reverse Osmosis Water Purifier (RO)
  • RO+UV Water Purifier
  • RO+UV+UF Water Purifier

Depending on the TDS level and other microorganisms that may be present, you can choose the optimal technology for purifying water.

Check out the below table to make an informed decision.

TDS Level Type of Water Purifier
0-500 UV Water Purifier
500 + RO+UV Water Purifier
Or Ro+UV+UF Water Purifier



In this current scenario, making smart decisions in all spheres of life is essential, so why leave the most important sphere - everyone’s health - behind?

A RO+UV water purifier like Cloudtap ensures 24/7 purified water with zero pathogens. This will help businesses to safeguard the health of all. Most importantly, since Cloudtap works on a subscription-based model, it offers zero CAPEX and maintenance, which makes it a cost-effective solution.

Thus, switch to this smart internet technology for water purification today to ensure the good health of all - customers and employees alike.

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