RO vs UV vs UF – Differences Between Water Purifiers

Gone are the times when people would go to the lakes and rivers for drinking water. Once, there was no fear of bacteria, viruses, or other harmful microorganisms in the water. Now, unfortunately, that is not the case. The world has evolved, and tons of inventions have emerged. Sadly, alongside those new and highly advanced inventions involve chemicals and other harmful properties that damage our natural resources – including our water sources.

Ironically and quite fortunately, society’s advanced technology is also what has brought the solution for this problem. Now, there are water purifiers present to make sure that people can drink the purest water possible. Various versions and methods have emerged, so much so that deciding which one to purchase and use depends on the user’s preferences. In light of that, here are three of the most commonly used water purifiers: reverse osmosis (RO), ultraviolet (UV), and ultrafiltration (UF). With each method’s brief summary and the pros and cons, we hope this article will help you decide which one suits your needs the most.


Reverse Osmosis Water PurifierUltraviolet Water PurifierUltrafiltration Water Purifier
Cleaning Methodthrough semi-permeable membranethrough ultraviolet bulb produced by the bulbthrough membranes that have larger pores
Pollutants That It Can Killbacteria and virusesbacteria and virusesbacteria and viruses
Ability to Remove Dead Bodies of Pollutantsyesnoyes
Ability to Remove Dissolved Saltsyesnono
Ability to Clean Muddy Wateryesnoyes
Electricity DependenceDependentDependentNot Dependent

Reverse Osmosis (RO) Water Purifier

The first among the three most common purifiers is the Reverse Osmosis or RO Water Purifier. The process involved is the exact opposite of the process called osmosis, wherein high-concentrated liquid flow to the low-concentrated one. In reverse osmosis, the liquid that has high concentration flows back to where there’s low concentration by use of force. This liquid then goes through a semi-permeable membrane, which filters out molecules by allowing the ones that are allowed to pass and blocking the ones that are not. 

The same concept applies to RO Water Purifier. In this process, two outlets are involved: one is for the pure or clean water to pass through, and the other is for the contaminated water. When done right, RO water purification can eliminate 99 percent (99%) of ions, total dissolved salts (TDS), molecules, and impurities such as bacteria and viruses. 

Two Types of RO Water Purifier

There are two kinds of RO water purifier: wall-mounted RO purifier and undersink RO purifier. Wall-mounted purifiers can store from 5 to 10 liters of water. They also contain water wastage that can be used in cleaning the house.  Undersink RO water purifier, on the other hand, is gaining more and more popularity for being a space saver and promoting tidiness. It can easily fit under the sink which helps in keeping the kitchen looking neat and organized. Moreover, its water storage containers are air pressurized so the clean water that comes out is stronger.

  • It kills bacteria and viruses.
  • It is able to remove viruses and bacteria.
  • It can remove heavy metals such as dissolved salts and lead.
  • Some versions of RO, specifically the ones with TDS Controller, are able to keep the water’s natural minerals.
  • It is easy to use.
  • It is compact.

  • It needs high pressure.
  • Only half of the amount of water you put into comes back as pure.
  • It needs electricity.

Ultraviolet (UV) Water Purifier

The process of UV water purification involves directly killing 99.99 percent of bacteria and viruses found in water using ultraviolet rays. This keeps these bacteria and viruses from reproducing in the water, making sure that it’s easier to clean. The ultraviolet light that kills these viruses and bacteria is produced by UV Bulb that can be found in the water purifier itself. The dead bodies of these bacteria and viruses need a separate filter to remove them from the water. This method is electricity-generated, but unlike the RO water purifier, there is no water pressure needed.

  • It destroys 99.99% of microorganisms.
  • It is chemical-free.
  • There is no by-product emitted, making it environment-friendly.
  • It only requires service once a year.
  • It works all the time.
  • It needs no reaction time.
  • There is no need for filter disposal.
  • It uses a low amount of energy.
  • It is compact.
  • It can be maintained easily.
  • It is cost-effective.

  • Scales may develop outside the bulb, blocking the ultraviolet light.
  • It cannot remove heavy metals like chlorine and salts.
  • It can only clean treat clear water, not water with other elements in it.
  • There is no backup purifier other than the ultraviolet light.

Ultrafiltration (UF) Water Purifier

The process of ultrafiltration water purifier compares to that of reverse osmosis water purification. However, ultrafiltration uses a semi-permeable membrane that has bigger pores. With those, it can kill a number of bacteria, viruses, and harmful microorganisms. Another good thing about this is that it removes the dead bodies of bacteria and viruses it kills. This water purifier works well with tap water as it does not necessitate the use of tap water pressure.

  • There is no need for electricity.
  • It can kill water pollutants such as bacteria and viruses.
  • It removes the dead bodies of the water pollutants.
  • It can clean both clean and muddy water.
  • It does not need much maintenance.
  • It has sturdy membranes that ensure the production of clean water.

  • It cannot remove dissolved salts.


Each purifier is about as effective as the other and it’s ultimately up to you and your preference when choosing which one is the best. You only need to review each method’s pros and cons so you can wisely determine which one will be the most helpful to you.

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