How to choose water purifier

How to choose water purifier

The predominant question one asks before buying water purifier is how to choose water purifier? Clean and pure drinking water is the first step to stay healthy and prevent diseases. Water purifier has become a necessary house-hold item. It is an efficient and inexpensive way to get pure drinking water for your family. If you own a right kind of water purifier, you can easily clean your tap water effectively, with the assurance of purity. Some people easily get carried away with sales people gimmicks. It is essential to do thorough job in figuring out the right purifier to suit your needs. So, how to choose water purifier, as per your needs? Please go through the below buying guide. We have attempted to answer all important questions before you buy water purifier.

In case of any clarification, feel free to post that as comments. We will get back with the answers.

How to choose water purifier | Things to consider before buying a water purifier

(The factors are ordered in terms of importance)

Water quality

The most immediate question that follows ‘How to choose water purifier’ is ‘what is the water quality?’.  The quality of water largely depends on the source and supply of water to your home.

It is imperative to be aware of the TDS (Total Dissolved Salts) present in the water. TDS value greatly helps in choosing the type of filter.

Different source of water includes Municipal water, Ground water and multiple sources and accordingly TDS level varies.

Water ChannelSource TDS Level
Municipal waterRiver, municipal corportation, lake1-200
Ground waterTubewell, Borewell200-2000
Multiple sourcesMultiple sources like municipal, borewell, tankerTDS varies day by day.

Depending on the level of TDS, water is considered soft or hard water. Soft water has TDS level of 150 – 300, wheareas Hard water has TDS level higher than that. As mentioned above, the type of water purifier needed greatly depends on the TDS level, salinity and hardness of water.


Storage is another factor to be considered before buying water purifier. Many people overlook this factor of storage capacity. Storage capacity in water purifier helps you to get continued supply of pure water even in the absence of electricity. You may wonder if storage capacity is that important to be considered and how to choose the right capacity for the water purifier you buy. Your decision on storage capacity is attributed to the type of purifier and  number of members in your family. The most common RO purifiers are of electrical type, whereas low cost purifiers are of non-electrical type.  Water purifiers are available in various storage capacities like upto 7L, 7-10L, 11-14L, above 14 L.

Electrical or Non-Electrical

While it is not an important factor, it will be helpful if you are looking for low-cost, portable water purifier (like Gravity, UF water purifier) for drinking water of low TDS level. UV purifier or RO purifiers are electric water purifiers; In case you opt for such purifiers, ignore this factor of electrical or non-electrical. Only Gravity and UF water purifiers are available as non-electric water purifiers.

Types of water purifier

There are different types of water purifiers in the market – UV purifiers, the most common RO purifiers, hybrid water purifiers, Gravity water purifier etc. There are also some common myths floating around that RO purifier is bad for health which I will cover in a separate article. Understanding the various types of water purifier is important if you are looking for buying one according to your needs. In fact, The query ‘what are the types of water purifier’ is tied to the question ‘How to choose water purifier?’ Without the knowing the types of water purifier and why it exists, we cannot arrive at buying decision.

UV purifiers

UV (Ultraviolet) water filters/purifiers employ ultraviolet purification technology using powerful UV lamp to purify water. The UV radiation penetrates the microorganism, passes through the cell body and then prevents its reproduction. It does not removed the sterilized micro-organisms but it is not harmful. It is also ideal for removing pesticides and make it safe for consumption. UV purifiers do not remove dissolved impurities like pesticides, chlorine, arsenic etc. UV purifiers do not alter the taste of water. It can be either advantage or disadvantage. Because, if the incoming water has bad odour, it continues t remain after being purified with UV purifiers. Considering these capabilities, UV water purifiers are mostly suited for water with low TDS level.


  • Removes bacteria, virus, cyst and microorganisms
  • No wastage of water like in RO purifiers
  • Low maintenance cost
  • Doesn’t change the taste of water
  • Doesn’t remove the essential minerals in water


  • Doesn’t not remove sterilized micro-organisms
  • Doesn’t not remove dissolved organic and inorganic impurities
  • Not ideal for muddy water. In that case, water has to pass through another purifier before UV purifier. It is suited for low TDS water

RO Purifiers

RO (Reverse Osmosis) water purifier employs reverse osmosis technique. It works by squeezing water through a semi-permeable membrane and makes water get rid of heavy metals and impurities. RO purifier is an effective purifier for water with high TDS level where contamination levels are high. RO purifiers, typically, come with prefiltration techniques to clean muddy water. The good RO purifiers retain minerals in the water. It is recommended to ensure the retention of minerals in RO purified water.

It is available in different range depending upon technology membranes and storage capacity. High wastage and high maintenance cost are the disadvantages of RO purifiers. More water gets wasted when compared to the filtered water. The wasted water, however, can be used for other purposes like cleaning the house etc.


  • Most common purifier in houses and companies
  • Ideal for hard water. Eliminate heavy metals and harmful chemicals
  • Effective for TDS (200 to 2000)
  • Good RO purifiers can improve taste and odour of water
  • Good RO purifiers retain minerals in the water


  • Water wastage
  • Maintenance cost
  • Not as effective as UV purifiers in removing micro-organisms. (That’s why, typical RO purifiers are combined with UV to ensure removal of micro-organisms)

UF Purifiers

UF (Ultrafiltration) water purifier uses semi-permeable membrane (like RO) to purify water. Then how does it differ from RO? The hollow pores in the membrane are bigger than the membranes in the RO. The bigger hollow pores bring their own advantages and disadvantages. Because of the larger pores, it doesn’t require additional pressure as water can pass through easily. It doesn’t require electricity.  Disadvantage is obvious that the purification is not as effective as RO. It only removes micro-organisms; it cannot remove dissolved solids. It also needs frequent cleaning to remove impurities stuck in membrane.


  • Ideal for water with Low TDS level
  • Does not use chemicals to purify
  • No electricity needed
  • Low Maintenance
  • Removes micro-organisms


  • Not suited for Hard water
  • Frequent cleaning required

Gravity water purifier

Gravity water purifer uses simple pressure filtration technique to purify water. It will be effective only for soft water with low level of TDS. It does not need electricity and it is inexpensive. It filters only physical impurities like mud and dust particles. The another advantage is gravity purifiers are portable. Hence if you are going for an short outstation, you can take this purifier along with you.

Considering its capabilities, Gravity based purifiers can be preferred when the optimal conditions for installation are not available for RO/UV/UF purifiers. If you have only hard water in that situation, then better get soft water from outside and then filter it through Gravity based water purifier.


  • Low cost (range from 1000 – 4000)
  • Electricity not needed
  • Low maintenance as filters are low cost
  • Portable


  • Suitable only for Water with low TDS level (less than 200 PPM)
  • Cannot remove germs (if not UF based) and filter out chemical contaminants and heavy metals like lead and arsenic


The choice of water purifier largely depends on the water quality, measured in terms of TDS and contaminants level. If the criteria is non-electrical and water is of low TDS, go for UF purifiers. If the decision circles around low maintenance cost and TDS level of water is low, then UV purifier is the suitable one.

It is undeniable that each types of purifier has its own advantages and disadvanges. In fact, standalone RO purifiers are not as effective as UV in eliminating micro-organisms. That’s why multistage water purifiers came into existence which ensures purified water with retention of minerals. However, it has, comparatively, high maintenance cost.

It is to be noted that RO purifier based hybrid purifiers are widely used in homes and companies, suited for high contaminated water. And they are also available in different price range based on storage capacity.

The most common question people ask is how to choose water purifier and without doing any research, they end up buying water purifier as per sales person’s words. We hope this article – how to choose water purifier – serves you to buy right water purifier according to your needs. Great! Now you have got enough information before buying water purifier. Please feel free to ask questions, we will get back to clarify your doubts. 

This Post Has 2 Comments

  1. Really good summary! Worth reading before buying a water purifier.

    1. Thanks for the feedback!
      Do read our list of best water purifiers if you would like to buy water purifier.

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