How to check TDS of water

Are you searching for the water purifier best suitable to your needs? Do you find yourself asking the question how to check TDS of water at home?

You have landed on the ultimate article, where we are going to discuss precisely how you should go about checking the TDS of input water. We shall discuss ways to check the TDS of input water, what are the acceptable limits, and how to regulate the TDS.

What is TDS?

TDS stands for total dissolved solids. TDS in water is mostly contributed by the inorganic and organic impurities which are present in the water. These include salts like magnesium, sodium, potassium, fluorides, carbonates, and sulfates. Additionally, there are a lot of dissolved inorganic metal impurities like lead, arsenic, mercury etc.

Most of these impurities are accumulated by the runoff water through the lakes, ponds, pipes, surfaces, farm fertilizers, industrial waste dumps etc.

The dissolved organic and inorganic impurities are extremely harmful for the body and are considered as slow poison. While, it is evident that the water with high TDS is harmful due to the dissolved impurities; lack of TDS in water can render it to be tasteless and void of essential minerals required by the body.

Therefore, it is very important to regulate the TDS to an acceptable limit using water purifiers.

Is TDS necessary?

Absolutely pure water which doesn’t contain any mineral; or zero TDS is tasteless and unhealthy for consumption. The drinking water should contain some essential minerals like calcium, magnesium etc. which are necessary for the nutritional value as well as the flavor.

Let us now take a look at the acceptable limits of TDS in drinking water.

TDS – Acceptable limits

The Bureau of Indian Standards (BIS) defines the acceptable limits of TDS in drinking water. According to BIS, the TDS value of 500 mg/ liter in drinking water is acceptable. Any TDS value higher than this makes the drinking water unfit for drinking. The following table clearly defines the TDS ranges of drinking water and their corresponding ratings.

TDS level mg/literRatings
Less than 50Unacceptable – water with such low TDS doesn’t contain the required
mineral necessary for the human body.
50 – 150Acceptable – It is an acceptable level since it contains low levels of impurities;
but the essential minerals concentration might be low
150 – 300Excellent – Ideal for consumption
300 – 500Good – Acceptable for human consumption. According to BIS,
water TDS levels till 500 are good for human consumption
500 – 900Not good – should not be consumed
900 – 1200Poor – unfit for human consumption
Above 1200Unacceptable – Contains a very high concentration of industrial wastes and other impurities

How to check TDS of water?

Having discussed what exactly TDS is and the appropriate levels of TDS in water, let’s take a look at how to measure the TDS of water.

There are broadly three different ways to measure the TDS of water. These are digital TDS meter test, test using the electrical conductivity meter, and lastly filter paper and weighing scale method.

The simplest out of these methods is the digital TDS meter test which doesn’t require an technical knowledge as compared to the other methods which need good amount of technical expertise. With the TDS meter easily available online, it is the most widely used method to measure TDS.

We will only be discussing about the digital TDS meter test, since it is easy and can be performed quickly at home.

Digital TDS meter test

The Digital TDS meter test is the easiest way to measure the TDS of input water at home. This test doesn’t require any technical knowledge whatsoever and a layman can easily conduct this test. Another advantage is that you don’t need to take any readings or apply mathematical formulae. The TDS meter has a display and the water TDS is displayed on the display directly and the results are immediate.

Buy from Amazon

You don’t even have to spend a lot of time searching for a TDS meter. It’s readily available on amazon at a very affordable price. You can check out the link above for the TDS meter which is used by a lot of customers already.

You can follow the following steps to measure the TDS of water using the above TDS meter:

  • Firstly, remove the protective cap at the top and switch on the TDS meter.
  • Dip the TDS meter in the water until the marking provided on the TDS meter. Usually it is somewhere around 2 inches.
  • Remove any possible air bubbles in water by gently stirring the TDS meter in water
  • Wait for around 15-20 seconds for the readings to stabilize
  • Once the reading is stabilized, take the TDS meter out of water while pressing the HOLD button
  • Check the reading, and replace the protective cap on TDS meter

Follow a few precautions by avoiding exposure of TDS meter to direct sunlight and avoiding completely submerging it under water.

Why should you remove excess TDS from water?

As we have seen earlier that the input water which comes to our home contains various organic and inorganic impurities. While the presence of salts like calcium, potassium, magnesium etc. is essential and required for the body, there are various undesirable impurities present in water.

The impurities can be accumulated from various sources including industrial wastage like arsenic, mercury, lead among other harmful metals. Needless to say, consumption of these harmful dissolved metals in water have the potential of making you very sick and are considered as slow poison.

Overall, these pollutants increase the TDS of water, and water having TDS above 500 is especially very harmful for the health. Due to all of these reasons, purifying and regulating the TDS of input water is extremely important.

Therefore, it is very important to regulate the TDS to an acceptable limit using water purifiers.

This should provide you enough reasons as to why you should make sure that the excess TDS from water is removed.

How to remove excessive TDS from water?

The excess TDS in drinking water can be removed using one of the three methods:


This process involves boiling the water to produce water vapors. As the vapors rise to the surface, they are passed through a separate tube where there are allowed to cool down and condensed back into the liquid form. Since, the dissolve salts and impurities are non-volatile they are left behind in the boiling water. The condensed water therefore, doesn’t have the TDS.

This is probably the easiest and the cheapest way to get rid of excess TDS in water.

Reverse Osmosis (R.O.)

Reverse Osmosis is a very popular industrial method for purifying water which is used in most of the water purifiers available in the market. This process involves forcing the water using high pressure through a semi permeable membrane to remove the excess TDS.

The membrane is very fine and contains microscopic pores which only allows molecules less than 0.0001 microns in size to pass through. As the result, the water molecules which are smaller pass through the membrane and the dissolved impurities which is larger is left behind.

RO is one of the best methods to complete get rid of the TDS in water.

As a rule of thumb, if the water TDS is higher than 500, then you should consider installing a good RO water purifier at your home.

Recommended Readings: Best Water Purifiers in India


The deionization process involves passing the water through positive and negative electrodes. As a result of this, the positive ion impurities are removed from the water as they are attracted and attached to the negative electrode. The resultant water is void of any dissolved ionic impurities.

This process however, is only capable of removing the dissolved ionic impurities. Further filtration is required to remove the non ionic impurities. Therefore, it is better to use RO water treatment instead of this method.


We have been gone through what is TDS in drinking water and why it is important to get rid of excess TDS in drinking water. By now, you should also be familiar with technologies suitable for treating drinking water with high levels of TDS.

If you might have any further questions, please feel free to drop a comment and our team shall get back soon.

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