TDS is a common terminology in use whenever you discuss water purification.

What exactly is TDS?  Let us look at this concept in brief.

Water is the Best Health Drink in the world that contains no fat, no calories, and no cholesterol. There are a lot of hazardous contaminants found in the drinking water that includes toxic elements, pesticides, radiological hazards and other pollutants.

Health Authorities often check the following to make sure that the water is safe.

  • PH
  • Presence of Dissolved Oxygen
  • Color
  • Hardness
  • Presence of the Bacterial Growth, Algae, algae
  • Total Dissolved Solids (TDS)

Total Dissolved Solids

A water molecule in its purest form contains 2 atoms of Hydrogen and 1 atom of Oxygen.

But, the water available from natural sources like rivers, lakes, and groundwater does not conform to this molecular formula.

This is because water contains a lot of organic and inorganic salts dissolved in it.

This water contains calcium, magnesium, sodium, potassium, sulfates, carbonates, nitrates, and fluorides among many other salts.

This seems to be a very long list, but the positive aspect is that you need a majority of these salts for your overall growth.

You need a certain proportion of these solids in your drinking water.

However, water can contain other contaminants such as heavy metals like arsenic, lead, and even mercury. These chemicals are dangerous and require elimination.

TDS up to a certain level is acceptable for human consumption.

It is only when the TDS proportion exceeds 500 (500 ppm) does it become hazardous. You would require the use of water purifiers to eliminate the excess TDS.

The Hardness of the Drinking water is created by naturally occurring substances like calcium (Ca) and magnesium (Mg).

Total Dissolved Solids (TDS) are the total amount of the mobile charged ions in a given volume of water which include minerals, salts, cations, anions, and metals.

TDS = The Total number of cations and anions in the water.

Rain Water is the Purest form of water, and the TDS of rainwater is few tens of mg/L.

TDS is represented in units of mg per unit volume of the water ( mg/l ) that is also referred to as parts per million ( ppm ).

The Dissolved salts come from both natural and inorganic sources. The Organic sources of the dissolved salts include leaves, plankton, trash from industries, pesticides, fertilizers and more.

Water will also pick up metals like lead and copper when it travels through the pipelines.

The Dissolved salts also come from the artificial sources such as rocks, atmospheric gasses, nitrogen iron, and minerals also.

Over time,  Water purifiers will lose the capability of removing the Dissolved salts from water.

You should observe the Quality of the membrane in your water filter and should replace it when required.

Please note that the presence of the Dissolved salts in water will affect the taste.

According to World Health Organization, TDS level less than 300 mg/litre is considered as excellent, between 300 and 600 mg/liter is good, 600-900 is fair, 900 – 1200 is poor and TDS level more than 1200 mg/liter is unacceptable.

In India, If the TDS level is above 500mg/liter, the water is considered as disagreeable. But, due to the lack of water resources, people are drinking water that has greater TDS Levels.

TDS in Indian Water

According to the BIS Standards, the maximum desirable TDS is 300 mg/l and maximum permissible is 600 mg/l.

WHO states that the water containing TDS concentrations below 1000 mg/litre are acceptable for the consumers. Lesser the TDS, Better the Water

How to Reduce the TDS in Water?

There are a lot of RO water purifiers available online that can reduce or remove the Dissolved salts in the water.

The most widely used Water Purifications Systems are Carbon filtration, Reverse Osmosis, Distillation, and Deionization.

In Carbon filtration, the Charcol consumes many toxic compounds when the water is passed through the activated charcoal.

Reverse Osmosis

Reverse Osmosis is one of the most commonly used filtration systems that removes all the dissolved contaminants in the water. The Only problem with RO is, It needs a lot of water.

The RO process splits the water into two parts and drives the dissolved salts out from the part into other.

As I mentioned above, Reverse osmosis requires a lot of water, and the wastage is also high.

If you input 3 Litres of Water into the RO Process, you will get one litre of Clean water and 2 liters of Dirty water.

So, when you are planning to buy a Ro Water Filter, Make sure you collect the dirty water and use it for cleaning the house. Don’t waste the Reject Water of Reverse Osmosis purification system.

The Cost of the RO Water Purifiers ranges from ₹8,000 to ₹15,000.

Read: Pros and Cons of UV Water Purifier

Please note that the Normal Ro Water Purifiers might not perform Good when the TDS level of the water is in thousands.



Distillation involves boiling the water and produce the water vapor that rises to a cooler surface and condensed back to liquid. Distillation is one of the oldest forms of water purification which is still used to convert the sea water to drinking water.


In this process, the Dissolved salts in the water are removed through the ion exchange. By Controlling the electric charge of the ions in the water, the Deionization removes the TDS from the water.


  1. My tap water TDS reading is between 300-330. Could you please suggest if UV+UF water purifier will suffice? Kindly reply ASAP.

  2. My new RO has reduced TDS to 43 (pureit eco). However, it has a mineraliser ( they call it TDS modulator). Should it be OK. Also plz tell if mineraliser enhances taste without increasing TDS.

  3. Hello Sir,
    The ground water for us is having some odd sewage smell. We were using KENT Grand and there are multiple filtering stages. I can see the TDS around 1000 from tap water and after filtration its around 50. But due to multiple filtration im facing frequent failures and keep on changing membranes. Now im planning to buy a new one with minimal filtration, as per your suggestion adding mineral cartridge instead of UV is one suggestion but is it really worthy? How can i rely on it? Carbon Sediment RO Mineral Post Carbon is this fine ?

  4. we use Ro system for our drinking water purposes.our row water TDS valuve is 70ppm and out put water TDs from ro system is it suitable for drinking purposes? Please give solution if it is not in safe condition.

    • It is safe only. But why use an RO water purifier when the TDS is already low. TDS 70ppm is already good. No need for an RO. It is safe but no need. Simple UV UF is enough

  5. My TDS is 750 and i am not sure of other values. I am against usage of RO as it would cause wastage of water. For this level of TDS is RO compulsory?

  6. TDS level is our drinking water is around 100 ppm but the taste is very salty. Please suggest which water purifier we should opt for.

    • The TDS readings might be wrong. Normally, if the water is salty, the tds levels will on the higher side. You can opt for a 100% RO water purifier that comes with a Mineralizer.

  7. Our water TDS level is 15 after RO filtered, is it good for health? How to increase TDS level by adding some consumeble food products (like salt, sugar etc). Or Is it good to idea to mix little amount of input (hard) water whose TDS is 765 or RO discharged water (which goes in waste usually during filtering process) whose TDS is 165, in order to increase TDS level of filtered drinking water..? Is there any harm in consuming such mixed water ? Please suggest.

  8. My Municipal Tap water sourced from deep borewell by Municipality provides 320 TDS water. Which purifier should I user. I was using Gravity based Pureit Advanced but from last 1-2 months I am seeing green algae depositing in lower filtered water container and also some white limestone type material floating at surface of purified water. My Germikit indicator is still OK and not Red. I am confused.

  9. Tds 79 is good. If your machine has RO UV facility, then you are advised to increase tds up to 100, which will be excellent, will provide tasty and adequate mineral containing water. Technician can adjust for 100 tds in RO UV machine.

  10. Hi, I just got my home RO system serviced and got 48 tds readings. Is it okay to drink and cook food or I have to get tds increased ?

  11. You require a reverse osmosis plant for that and according to the quantity of pure water needed starting from 25000 to 3,4,5,10 lakhs etc


  13. Hi I’m using Aquaguard enhance water purifier and the normal TDS value is 330PPM after using filter the TDS value is 30PPM.
    Do I need increase the TDS value in filter please let me know?

  14. Hi , we use borewell water, which has tds value of 180 ppm , we use livpure pep pro RO which current tds value is 79 ppm but am very confused with the technician from livpure as they say the ideal drinking water is below 40 ppm . You mentioned here the ideal water should be between 100 to 300 ppm . First of all do we need RO system as our borewell water showing 180 ppm and why the technician guys say below 40 ppm.

  15. Hi the water we use is from multiple sources (bore/ tankers) and TDS varies between 500 and 1500 depending on season. Which purifiers are good for TDS ranging from 500 to 2000 TDS?

  16. Hi Sir

    I am using MCD Water and having TDS Laval 145 , we are using low TDS membrane and getting output TDS 29. Is this ok for Drinking or not please suggest.

    • No need reduce the TDS levels in your water. 145 TDS is good. Just use UV/UF Purifier to remove bacterium and other suspended impurities.

    • The water having TDS levels below 25 might be deprived of some natural minerals. You can consume such low TDS water (Water purified via RO) when you are residing near to a chemical factory or the surroundings water is very polluted. Otherwise, there is no need to decrease the TDS levels of the water to such low ppm.

  17. I am using Borwell water for drinking purpose I have checked TDS it’s 450. Taste also quite good
    There’s is no factory nearby my flat.
    So should i go for RO

    • For TDS levels below 400ppm, RO water purifier is not required. In case you are not sure, you can go with an RO water purifier that comes with a TDS regulator/Mineralizer that retains the natural minerals from the water.

  18. Source of water is tubewell water and its tds is 320 -330…which water purifier will be best ??
    Suggest models

    • What is the TDS levels in your water source. Normally, Municipal supply water is already treated and if the TDS levels are low, you can go with a UV UF water purifier like Kent Maxx. If you are not sure about the TDS levels, it is better to go with an RO UV water purifier.

  19. Hi, The TDS level measured at my home is 400. Do I still need to buy a RO and what is the required TDS level for a human being to be getting the essential minerals from the water.

    • Water having TDS Levels 500ppm is good for consumption. You don’t need an RO water purifier for water having TDS 400ppm. In case you live near to a factory or a polluted area, it is better to go with an RO water purifier.

  20. what minimum value of TDS is recommended for drinking water to be safe for human (Below 300 is safe but below 100 is it useful to drink ?)

  21. I want to install water purifier at my home in Punjab.Punjab is struggling with impure water after fertilisers have spoiled the water.Cancer is also quiet prevalent.Please advise the one which is best for such conditions.

  22. Hello! I have my Tap water TDS at around 180-200. I’m interested in UF as TDS is well within the limits. I want to know how much will be the approximate result of TDS after Ultra filtration.
    And also how about we can use the traditional ceramic candle filter we used long back??Is it not enough?

  23. In Solapur, Maharashtra, water quality of tap supply is ( with reference to BIS 10500)
    tubidity 0.32
    pH 7.62
    Chlorides 168.0
    Nitrates 2.41
    total hardness 340 ( as CaCO3)
    alkalinity (as CaCO3) 322
    TDS 714
    Iron 0.06
    Fluoride 0.46

    Normally RO filters are being used but it is wasting lot of water. Please suggest method to save water while making it potable.

    • The TDS levels in your water are good. So, There is no need for an RO water Purifier. You can simply install a UV/UF water purifier at your home. The UV/UF water purifiers don’t remove the TDS from water but they are capable of removing the bacterium and virus from the water. Kent Maxx, Aquaguard Superb are the best selling UV/UF water purifiers.

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