How To Choose The Best Water Purifier for your Home?

Which water purifier should I buy? What is TDS? NF? UF? RO?

Today, health and overall well-being are considered important things among aware adults. It's no secret that water is essential for keeping our bodies running smoothly and efficiently.

Water can have many harmful contaminants which should be filtered for drinking purposes. Here comes the work of water purifiers. They are relatively small and a great investment, it's a machine that has become a necessity more than a luxury.

There isn't a single purifier that fits every household's needs and you should select a water purifier according to its water supply. If a brand is insisting on buying their water purifier because they have, say, 20 stages of filtration. Run, as fast as you can because more stages don’t mean better quality of water.

So, what's the right quality of drinking water? How to know which water purifier is the best for you? We've created a step-by-step guide for you to decide how to select the right purifier. Make sure to read further! 


What is the right quality of drinking water? 

Before we get to understand how purifiers work for you, let's go through the drinking water standards that are suitable for human consumption.

  • TDS or Total Dissolved Solids in drinking water is the amount of dissolved impurities such as metals, minerals, salts, ions in a particular volume of water. A TDS meter can be used to check the TDS of your water supply. It's inexpensive, just a few bucks and you're good to go. 
  • According to the World Health Organization (WHO), the ideal TDS of drinking water should be between 100-300. So, if the TDS of your drinking water comes out to be between 150-200, the water is fit for drinking purposes.

Learn more about the ideal TDS of drinking water, the pH level of water, and the factors that influence drinking water quality here.


Steps to Choose the right water purifier for your home 

This step-by-step guide will help you understand what are the important things you must know before you buy a water purifier for your home with regards to your safety. 

Step 1: Know Your Water 

The first and foremost step of choosing the right water purifier is to 'Know Your Water' which literally means understanding the quality of water you receive at your home. This will help you not only make the right decision but also makes you aware of the source of water you're getting at your home and how reliable it is. 

Every home has a different source of water such as municipal water supply, bore-well, natural sources like rivers or ponds, water tanks, or a mix of tanker water and municipal water and it needs to be purified differently.

Most people think that having an RO is the best solution for water purification but here's the catch, the National Green Tribunal (NGT) recently asked the government of India to put a ban on RO water purifiers in regions where TDS is lower than 500. Why? Well, essentially because: 

  • First, RO reduces the TDS of water by 95-98%. If ROs are to be used in areas where TDS is lower than 500, it can demineralize the water and such water is not fit for drinking purposes.
  • Second, RO rejects over 80% of water which is not justified. Water wastage is highly problematic, more so when the input water is already rich in minerals and fit for drinking.

Head over to ‘Know Your Water’ to learn more about your water quality.


Step 2: Identify Core Filtration Technology That You Need 

The next step is to carefully identify the technology that suits best for your household. Here are a few tips to make you understand what filtration technology might suit your home: 

  1. If TDS < 200, you may choose to not use NF or RO at all and just rely on MF or UF filtration. You may also choose to use 20% rejection NF just to be sure of getting rid of occasional impurities in case the source of your water is not reliable.
  2. If TDS < 1500, you can go for Nanofiltration Technology to get quality drinking water with healthy levels of TDS. Also, you must choose between NF - 20/40/60/80 carefully based on your supply water quality.
  3. If TDS > 1500, you should go for an RO filter with a rejection rate of 95%+.

Here is a simple chart that you can use to identify the core technology you need at your home. All these recommendations are made with regards to the recommendations made by the World Health Organization (WHO) and Bureau of Indian Standards (BIS):

TDS Levels of
Water Supply
Recommended Purification
0 to 90
Gravity filters, MF or UF
90 to 200
UF or NF20
200 to 350
UF or NF40
300 to 600
600 to 1500
> 1500


Add Ons:

  • UV - Ultraviolet filtration deactivates bacteria, viruses, and all other microorganisms. It’s a must-have with UF purification but is a good-to-have in the case of NF or RO water purifiers. UV Chambers should be made of quartz glass or stainless steel, nothing less.
  • Alkaline Filters - Alkaline filters are just chemical-based filters and they don’t remove any contaminants. There aren’t many side effects but no good effects either (at least there is no documented scientific study). Plus, they are unnecessarily expensive so why waste your hard-earned money. Find out more about the MYTHS surrounding alkaline water here.
  • TDS Adjusters - TDS adjusters are nothing but a bypass valve that mixes impure water with purified RO water to increase the TDS level of drinking water which defeats the whole purpose of purification. YOU DEFINITELY DON’T NEED IT!

  • Copper Filters - Copper filters do have their fair share of benefits but make sure you have the option to consume non-copper filtered water. Even Ayurveda recommends storing water in a copper vessel for drinking but with a limit of only 2-3 glasses of water a day.

  • Using a UF with RO or NF - Using UF purification with RO or NF doesn’t make any sense unless you are using a TDS adjuster (which in itself is just a marketing gimmick) since RO/NF membranes have smaller pore size than UF and they eliminate all micro impurities, leaving nothing for UF to purify.


Step 3: Know How Much You Are Going To Spend 

Buying a water purifier isn't just a one-time investment, and in order to get the best out of a purifier, you need to take care of it, meaning, you need to regularly change the filters for which the maintenance costs can be crazy expensive! 

  • Many big brands in this market like Aqua guard, Pure-it, Kent, and some others use custom-designed parts and filters which can only be bought from the brand itself which are very expensive and are also not easily available in the market.
  • So, if you have a water purifier purchased from brands like these, be sure to spend an average of ₹4000-7000 per annum on maintenance costs. So for 5 years of usage, you may end up spending around 20k-35k on the maintenance cost of your water purifier, which is more than the machine itself. Insane, right?
  • If you buy RO from local brands, you might end up saving some money on water purifier maintenance but with the cost of compromising the quality of water since local brands use cheap quality filters. So, we wouldn’t recommend you to opt for that as well.

To conclude, the maintenance cost of your water purifier might exceed the cost of the water purifier itself. So, be aware of the costs involved and make a smart choice!


In short

  1. Learn more about the source, TDS levels of your water supply, and the best TDS for drinking water.
  2. Select a purifier that doesn’t demineralize your water.
  3. Learn about the maintenance cost before making an investment.
  4. Don’t compromise with the quality of water.
  5. Buy what you need, don’t fall for the gimmicks.

        1 comment

        We have Borewell water and Cauvery water mix with TDS between 350-500.

        Jane Weidle

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