Which is Better - UV or RO Water Purifier?

2022-09-21 06:30:42Which is Better - UV or RO Water Purifier?
Which is better - UV or RO water purifier

Drinking pure and safe water is most important from a health point of view. Owing to the effects of pollution across the world, water bodies are contaminated and we no longer have a guarantee of getting safe drinking water. Even though the tap water is filtered before it is supplied to the homes, there is no guarantee that it is safe to drink because of cross-contamination between water supply lines and sewage pipes which are aligned parallelly  and also due to unclean pipes and storage tanks. You can never be sure that the water you consume is entirely safe.

Traditionally, people boil the water before using it for consumption. It is still considered as one of the most effective ways to filter impure water but it is not entirely practical. Though  boiling water may remove certain germs and pollutants, it can’t eliminate all the impurities. So, you must find a method that can eliminate various contaminants  that is also a better option in a  fast-paced world where you’re always short of time.  Installing a water purifier at home can be that option.

The sort of pollutants in your water will determine which filtration technology is best for you. Is the major issue microorganisms (bacteria, viruses, and cysts) or dissolved pollutants like iron, fluoride, calcium, and magnesium in the water? When these questions are answered, one usually feels relieved.

Water purifiers have become one of the most important kitchen appliances today. With several options available in the market, it is natural to get overwhelmed while choosing the right water purifier for your home. However, if you consider a few factors like water quality, technology, storage capacity, and budget, choosing the water purifier will be much easier.

Water quality is the most important determinant of the kind of water purifier required for your home. If the water has more percentage of TDS then it is important to install RO purifiers at home, and if the water has a permissible level of TDS but has more microorganisms, then  it is advisable to buy UV water purifiers.

In this article, we are going to discuss the difference between RO water purifiers and UV water purifiers and which are the best and understand which one to buy when

What is RO?

Reverse osmosis, generally called RO, is one of the most effective purification methods. Reverse osmosis is one of the most refined methods of water filtration, and it can improve water quality and taste, even when the water is already treated. Reverse osmosis is a water purification process that uses a semi-permeable membrane (synthetic lining) to filter out unwanted molecules and large particles such as contaminants and sediments like chlorine, salt, and dirt from drinking water. In addition to removing contaminants and sediments, reverse osmosis can also remove TDS and toxic metals – which you certainly do not want to drink. It gets water clean and healthy leaving only pure H2O behind.

Among various purification methods, RO is the only purification process method that can eliminate TDS in the water and make it fit for consumption. It is an effective and environmentally friendly purification system. RO water purifier is designed using the natural process existing in the environment. It uses a semipermeable membrane to clean the water.

As a water treatment process, reverse osmosis provides many advantages, including:

Benefits of using RO purifiers:

  1. Total dissolved solids reduction: Reverse osmosis is one of the rare water treatment processes that can boast a total dissolved solids reduction. The few other treatment methods with this capability are often less efficient than reverse osmosis.
  2. Cost-effectiveness: Reverse osmosis is popular in industrial settings because it is highly economical compared with alternative filtration methods. It allows plants to treat large volumes of water while remaining comfortably within their established budgets.
  3. Alkalinity and hardness removal: Reverse osmosis removes the calcium and magnesium ions that contribute to hard water, as well as the carbonate ions that contribute to unwanted alkalinity.

In today’s urbanised environment, water tends to get more contaminated and gets mixed with various harmful impurities. Altogether they add to more percentage of TDS (total dissolved solids) in the water. TDS contains minerals, heavy metals, harmful chemicals, organic and inorganic matter, microorganisms, and other particulate matter.  Water with high levels of TDS is not potable and hence needs to be purified.

How does RO work?

Reverse Osmosis water filtration process is simple and straightforward. It is accomplished by water pressure pushing tap water through a semi-permeable membrane to remove contaminants from water. This is a process in which dissolved inorganic solids are removed from a solution. This process differs from standard filtration where impurities are collected within the filter media. In a reverse osmosis process, the water flows through the membranes at high pressure where it removes TDS, fluoride, harness and other heavy metals providing you safe and clean drinking water.

A RO water purifier uses a multi-step process to filter the water. It consists of 3 main components:

  1. Pre-RO Stage
  2. RO stage
  3. Post-RO stage

In the pre-RO stage, there are generally 2 filters that purify the water initially. The sediment filter and the pre-carbon filter remove the sediments and some suspended particles present in the water. The water then moves to the RO stage.

In the RO stage, an applied pressure pushes the water towards a porous membrane. This semipermeable membrane has such tiny pores that it can allow only water molecules to pass through. So when the water is pushed through the membrane, all heavy metals and other dissolvants are caught behind it while just pure water flows through. Therefore, the impurities (TDS) are separated from the water.

 In the post-RO stage, the water is purified again, with a post-carbon filter which removes any remaining impurities in the water. A carbon filter will also remove bad odour and also polish the taste of the water.

Advantages of RO

RO purification has various benefits such as:

  • It can remove multiple impurities
  • It can transform hard water into soft water
  • It can sweeten the water by removing the salty taste
  • It can eliminate the bad smell in the water

Here are some of the top RO water purifiers to consider:

Pureit Classic G2 RO+MF 

The HUL Pureit Classic G2 Mineral RO + MF water purifier offers advanced 6-stage purification. 

The purification process guarantees that all water passes through RO, ensuring that clean and unclean water does not mix, resulting in RO filtered water that is 100 percent purified..

It has a filter life of 6000 litres, which is twice that of ordinary filters. It has a minimal maintenance cost, bringing the per-litre cost down to around 50 paise.

What is UV?

Ultraviolet water purifiers, as the name suggests, use  UV radiation to purify the water. It is specially designed to kill microorganisms like bacteria, viruses, parasites, and cysts in the water. Sometimes even if the water doesn’t contain other impurities, it may contain germs which can be a potential threat to our health. Hence, it is important to remove these microbes from drinking water. Although RO purifiers can flush out dead microbes, they can’t kill them. That’s where UV comes into picture.

How does UV work?

UV water filters consist of a UV lamp that emits UV radiation. So, when the water enters the UV chamber, the lamp emits the radiation, penetrates the microbes, and attacks their DNA,  killing them easily. Hence, UV water purifiers are important.

Differences between an RO and a UV?

To summarise, if the tap water source at your home is municipally supplied surface water, the TDS (dissolved impurities) are likely to be low, and you just need to protect yourself against microbiological pollutants such as bacteria and viruses. However, if your water is from the borewell, there may be a higher level of dissolved pollutants, altering the flavour of the water and affecting your long-term health at higher levels of TDS (above 500 ppm) and you might need an RO water purifier to treat it.

  • Impurities

The first thing to understand about RO and UV water purifiers is that they operate in very different ways. UV filters are intended to kill bacteria and viruses, whereas RO filters are intended to remove TDS and dead microorganisms from the water. RO systems have the advantage of using activated carbon, which improves the flavour of the water.

It's also worth noting that while UV purifiers can kill bacteria, they can't eradicate them. This means that the water you drink still contains dead bacteria. They are, however, completely harmless.

Although RO membranes do not have the power to kill germs like UV lamps, they are able to remove them totally. You should opt for a purifier that has both UV and RO capabilities to achieve the best results i.e. killing live bacteria as well as removing dead bacteria.

  • TDS (Total Dissolved Solids) in the Input Water

The TDS in your home's input water is the most significant thing to consider while deciding between these two types of water purifiers. 

It is a popular belief that  eating and drinking items in their natural state is always a good idea. That is not necessarily true. If the TDS in the input water is less than 300ppm and we only want to eliminate microorganisms, UV water purifiers can do the job effectively while preserving the natural composition of the water.

  • Water Conservation

UV channels do not waste with regards to water squander. The greater part of these purifiers squander north of 650 millilitres of water for each litre of water handled, yielding only 350 millilitres of drinkable water. Pureit Eco Water Saver purifiers are equipped with Eco Recovery Technology, an additional feature that offers excellent water purification along with high water savings as compared to other ROs. With this technology, these purifiers wastes less than 1 glass per purified water whereas other ROs waste up to 2.5 glasses per glass of purified water.

However, the water can be sent into a reject tank for recycling, where it can be used for various home duties such as watering plants, cleaning and washing clothes but not for drinking.

  • Storage tank

Reverse Osmosis filters, unlike UV purifiers, have a storage tank where water is held after it has been filtered. Depending on the type, most of them come with a 5-10 litre storage tank. However, some recent UV water purifiers might not include a larger storage tank.

  • Maintenance

To achieve the greatest results, both RO and UV purifiers require regular maintenance. But with Smartsense Indicators, Pureit RO + UV purifiers offer automatic indicators that help you to know when to replace your Germkill Kit or Sediment filters. Hence, you would need to change the filters only when it is required. UV water purifiers, on the other hand, employ solely UV lamps and may include a sediment prefilter in higher models. These purifiers are less expensive to maintain since they are comparatively simpler in technology.


It is not wise to rely on a single filtration technology because each has its own set of advantages and disadvantages. A multi-stage purification technique with several purification technologies is universally preferred. 

As a result, we propose water purifiers with a mix of RO, UV, and UF, as well as a TDS controller/modulator or mineraliser. Most Indian houses can benefit from these water filters.

Both RO and UV water purifiers have an important role to play in water purification. Depending on the water quality and your requirement, you can choose the water purification system. 

To ensure your water is fit for consumption, a multi-stage purification system like RO+UV is considered best.