WaterFilterGuru content is free. When you make a purchase through referral links on our site, we earn a commission at no extra cost to you. Learn more

Purified vs Distilled Water: The All-You-Need-To-Know Guide

purified vs distilled water

What is Purified Water?

Purified water is water that has very low levels of total dissolved solids. There are lots of water filtration methods available for producing purified water, including reverse osmosis, distillation and more. Reverse osmosis provides the most thorough filtration that removes up to 99% of all TDS, allowing water to have less than 10 PPM, or parts per million.

You might be asking:

“Is distilled water purified water?”

Essentially, yes.

Or to be more precise, distilled water is simply a type of purified water that’s made using a distillation method.

We’ll cover more on that later in the article.

Advantages of Purified Water

Relatively low-energy process

When we compare the way purified water is produced vs the way distilled water is produced, mechanical filtration methods require lower energy throughout the process. Far less energy is required to filter water than is needed to distill water via boiling it to remove contaminants.

Clean, fresh tasting water

Filtration techniques, and especially reverse osmosis, removes up to 99.9% of all total dissolved solids in drinking water, making it almost completely pure. This pure water is far cleaner and safer for drinking than standard tap water.

If you’re concerned about the health implications of drinking water that contains metals, chemicals, pathogens and environmental pollutants, you’ll much prefer to drink reverse osmosis water.

Remineralization option

Many people enjoy the taste of mineral water, but when it comes from a water bottle, it may also contain traces of contaminants that aren’t so great for your health.

Instead, a safer method is to produce pure water through water filtration, then use a remineralization filter to add just these calcium and magnesium minerals back into water. Many filtration units come with a built-in remineralization filter, so you won’t need to buy one separately.

Immediate results

Many filtration techniques offer an incredibly speedy process, and it takes just seconds for water to pass through all filtration stages. As filtered pure water is stored in a tank, you won’t have to wait for your faucet to dispense water after you turn it on – water will flow straight out of the tank and into your drinking glass.

what is purified water

Disadvantages s of Purified Water

Costly process

You’ll need a bigger budget if you’re considering purchasing a reverse osmosis system for producing purified water.

These systems can cost up to $3,000, with some priced at even higher than that. You certainly get what you pay for, as reverse osmosis is an incredibly efficient water filtration method, but it’s a large investment to pay upfront.

Remember also that you’ll need to factor in costs for regular filter changes. Your RO unit won’t continue to work properly without regular filter changes as advised by the manufacturer.

Usually, you’ll need to pay for new carbon filters, pre filters and post filters every six months to a year. The RO membrane lasts slightly longer, at up to 2 years.

Depending on your model, can either buy filters on their own, for around $15 to $20, or buy the whole set, for around $40 to $80.

Produces water waste

Compared to other filtration methods, reverse osmosis is the only type to produce water waste.

There is no preventing this, as the reverse osmosis process wouldn’t work without it. However, some systems use a booster pump to send water through the RO membrane at a faster rate, which reduces how much water goes down the drain with the impurities and contaminants.

RO doesn’t produce any more water waste than the average household water-based appliance, like a washing machine, but it will still have a small impact on your monthly water bill.

Requires more complex installation

Household water filters are complex by nature, and although most systems are designed for at-home set-up and come partially assembled, there’s still a fair bit of complex installation you’ll be expected to do at the beginning.

The biggest task is to connect the unit up to the cold water line underneath your sink or at the point of entry into your house. If you have little to no plumbing experience, this might take a bit of extra effort.

Some reverse osmosis systems also have separate faucets, which you’ll need to install at your kitchen sink. The system won’t work without this faucet, so there’s no avoiding this part of the installation.

Removes healthy minerals from water

It’s part of the package of purified water: the good impurities are removed with the bad. Water filtration removes up to 99.9% of all TDS from water, including healthy minerals like calcium and magnesium.

Although it’s not the end of the world if your water no longer contains these – you can get them in higher quantities from food sources, after all – you might prefer the taste of mineral water. In this case, you’ll need to look specifically for a unit with a remineralization filter, or buy one of these filters to install separately.

Requires high water pressure

All households have slightly different water pressures, and if yours is too low, your water filter may not be as efficient. If you are looking at a reverse osmosis solution, keep in mind the process relies on a high water pressure to force water through the RO membrane quickly enough to minimize waste and fill the water tank faster.

If pressure is too low, water will linger in the space before the RO membrane, where it will be flushed down the drain with any impurities. You might need to purchase a booster pump to improve your water pressure if it measures lower than 30 PSI.

How is purified water made?

Purified water isn’t so elite that you can only buy it in water bottles. If you invest in a water filter that is highly efficient at removing contaminants from water, like a reverse osmosis unit, you’ll be able to benefit from purified drinking water every day.

When you turn on the faucet, water flows straight from the water line into the RO unit, where it is filtered, before returning to the water line and dispensing out of the faucet.,

Here’s how purified water is produced through the process of reverse osmosis:

  1. Water enters the reverse osmosis unit from the main water pipe. It flows through the first filter in the unit, which is normally a pre sediment filter. This filter removes larger particles from water, like sand, dirt, dust, and anything else that might be noticeable to the human eye. It’s important that this sediment is removed immediately from water, as it could clog up or damage the later filters and RO membrane if it was left in.
  2. The next stage of filtration is usually an activated carbon filter. This filter is usually made from organic material like coconut shell or charcoal, and is designed to cover as much surface area as possible, enabling it to catch contaminants like chlorine and pesticides in its pores.
  3. Water is then pushed at a high pressure through a semi-permeable reverse osmosis membrane. It’s this process that makes reverse osmosis a standout filtration method compared to others. During the reverse osmosis process, the water particles can pass through the tiny holes in the RO membrane, while any contaminants are trapped on the other side. These contaminants are consistently flushed away along with water that hasn’t yet passed through the membrane. For every 1 gallon of pure water that is produced in reverse osmosis, around 3 to 4 gallons are lost. After water has passed through the reverse osmosis membrane, it will usually travel to a storage tank, which will let out water when you turn on the faucet. Every time you use water from the tank, it will automatically refill itself, preventing you from ever having to wait for more water.
  4. Most RO systems commonly have a final carbon filter to remove any lingering sediment from the water that might have leached into the water in the storage tank. This filter polishes water and makes one final effort to improve taste and odor before water reaches the faucet for drinking.

water purification process

You can see from the outline of reverse osmosis that a lot goes into the process, enabling the largest number of contaminants to be removed from water at one time. The water produced by reverse osmosis contains very little impurities, as it has passed through a number of different filter stages designed for removing particles of varying sizes. This is why reverse osmosis water is considered pure.

It’s worth mentioning that some reverse osmosis units utilize a remineralization filter, which adds minerals like calcium and magnesium back into water. Many people enjoy the taste of mineral water, and it’s also healthier for you than pure water – but that doesn’t mean you can’t get your minerals elsewhere.

If your RO unit remineralizes your drinking water, it technically won’t be considered pure. However, these impurities are not actually considered bad for you.

What is Distilled Water?

Distilled water, as we mentioned earlier, is actually just a form of purified water. Like purified water, distilled water contains a total dissolved solids level of less than 10 PPM, making it extremely pure. As the name suggests, this type of pure water is made through the process of distillation.

The biggest difference between distilled water and purified water is the method used to produce the end result. While purified water is made through various methods of filtration, distilled water is made in an age-old process that has become modernized to what it is today.

How distilled water is made?

You can make distilled water yourself using just a few basic kitchen staples, but this tends to take a very long time.

Luckily, if you want to distill water from home, there are now distillation machines that simplify the process and effectively do all the hard work for you. All you’ll need to do is set one up, fill it with water and switch it on.

Most water distillers are electric, so they’ll need to be installed near a power supply. You can either store your distiller on your countertop or under your counter, and as you’ll need to manually add water to it, it’s important to place it in close proximity to a kitchen sink.

Water is produced through distillation following these processes:

  1. Once you’ve added water and switched the machine on, distillation can begin. Water heats up in the boiling chamber, and then evaporates, forming steam.
  2. When this steam rises, it passes through a vent and into a condenser, a stainless steel tube. The contaminants, impurities and pathogens that are unable to take on a gaseous state are left behind in the boiling chamber.
  3. Inside the condenser, a fan chills the steam, turning it back into a liquid through condensation. The steam forms water droplets, which flow through the condenser tube and into an activated carbon post filter.
  4. The job of the activated carbon filter is to remove any contaminants from water that may have been able to convert into gas particles during the boiling process. The filter uses the process of adsorption to trap contaminants in the water and prevent them from passing out of the other side of the filter.
  5. Water drips from the activated carbon filter into a glass or plastic holding tank. It may take several hours for this tank to fill to the brim.

Like reverse osmosis, the water distillation process is very thorough.

Evaporating and condensing water is an effective enough method of removing contaminants from water, but with the added activated carbon post filter, virtually no contaminants are left behind in water that passes into the holding tank.

You can also find water distillers that include remineralization filters for introducing magnesium and calcium back into water. If you prefer the taste of mineral water, a distiller that remineralizes water might be for you – but keep in mind that remineralized water isn’t considered completely pure.

You might also like our article about the 10 best water distillers

home water distiller

Advantages of Distilled Water

Contaminant-free water

Water distillation is one of the most effective ways to purify your water. It does so much more than water filters, which only reduce contaminants from water, not remove them completely.

In the process of distillation, the majority of contaminants are simply unable to turn to gas, which means they can’t pass through to the condensing chamber with water. Any that can turn to gas are filtered out with a carbon filter, making for a highly efficient removal of all contaminants from water, vastly reducing your risk of consuming any harmful chemicals.

Lower cost filtration option

Compared to reverse osmosis units, at home water distillers are a lot cheaper to buy upfront. You can buy a distillation unit for between $75 and $150, and it’ll do exactly the same job at removing contaminants as RO filters.

Water distillers are the lowest cost method of producing purified water.

Simple installation

If you’re distilling water using a distiller, you won’t need to spend hours putting the machine together before you can use it. Most distillers come almost completely assembled, and you’ll just need to plug them in, add the filter, switch them on, and they’re ready to go.

Sometimes you might need to complete very basic installation tasks, like adding the handle to your storage tank, but that’s about as intense as it gets.

As a distillation unit isn’t connected to your main water pipe, you won’t be required to carry out any complex plumbing installation.

Remineralization option

Like reverse osmosis units, some distillers come with their own built-in remineralization filters for adding calcium and magnesium minerals back into water.

This option is there for you if you prefer the taste of mineral water, or still want to get the health benefits of drinking water with added minerals.

Disadvantages of Distilled Water

Lengthy process

The distillation process is by far the longest water filtration process of them all. When water condenses from steam, it does so literally droplet by droplet. This means you’ll need to wait for your storage tank to fill by water drips, which can take several hours. In comparison, water purification via reverse osmosis takes just seconds.

Water distillation is by no means an immediate method of producing pure water, so you’ll need to plan ahead or leave your machine running overnight if you want to use a batch of distilled water at one time.

Consumes a high amount of energy

Water distillation is also a very high energy process.

The water needs to be boiled until there’s nothing left in the boiling chamber (apart from the contaminants), which takes a lot of energy. Reverse osmosis still uses a substantial amount of energy, but is generally a more efficient process if ingoing water pressure is high enough.

Removes healthy minerals from water

The water distillation process is so effective, it removes almost all impurities from water – including removing healthy minerals like potassium, calcium and magnesium. If you like drinking these minerals in your water, you’ll need to find your own means of adding them back in, or purchase a remineralization filter.

Requires regular upkeep

A water distiller won’t continue to work efficiently without regular upkeep.

With every batch of distilled water produced, a variety of contaminants are left behind in the boiling chamber, which may lead to a build-up of bacteria and other harmful microorganisms. Calcium and magnesium will also leave limescale deposits on the inside of the boiling chamber, which become more difficult to clean the longer you leave it.

Most manufacturers recommend you at least rinse out your boiling chamber after every batch of distilled water, and you’ll need to subject your machine to a deeper clean on a once-weekly basis. Remember also that a distiller’s carbon filter will require changing every four weeks or so.

Common uses for distilled water

There are so many uses for distilled water, many of which you might not even be aware of. If you don’t know whether a water distiller is worth it, take a look at all the different ways you can use distilled water around your home:

For drinking

The main reason why most people want to invest in a water distiller is to produce distilled drinking water.

Oftentimes municipal tap water across the US is laced with hundreds of trace contaminants, which can give water an unpleasant taste and smell, pose health risks, and reduce water quality.

Distilled water is about as pure as you can get. It doesn’t contain any of these impurities, making it far cleaner and safer to drink.

Adding to a humidifier

The water that you add to your humidifier directly affects the quality of the air you breathe in. If you add standard tap water to your humidifier, bacteria and other microorganisms could collect inside your unit, which would result in a production of unhealthy air for your home.

Certain tap water minerals are also responsible for spreading dust and allergens, which you can avoid by adding distilled water instead.

Vehicle maintenance

When it’s time to add water to your car’s cooling system, it’s a far better idea to add distilled water. The minerals and contaminants in normal tap water could cause corrosion or even limescale inside your system, making it less safe and practical to use regularly. Distilled water is mineral and contaminant-free, and can help your car to stay in peak condition.

Home aquarium

The quality of the water you add to your home aquarium is essential for keeping your fish healthy and happy.

The minerals and chemicals in normal tap water will eliminate the healthy bacteria that your tank needs to survive and cause an ammonia spike, which could kill your fish. Distilled water contains no chlorine, and is one of the best options for a healthy home aquarium.


Ironing with normal tap water risks clogging the iron with minerals that leave hard water limescale deposits. Limescale shortens the lifespan of irons and makes them less efficient. Distilled water, on the other hand, contains no limescale-causing minerals and won’t cause damage to your iron over time.

Watering plants

While it’s fine to water your plants with tap water, if you really want to treat them well, using distilled water is best. Chemicals like chlorine and pesticides found in traces in tap water can harm plants and contaminate soil.

Distilled water is clean and contaminant-free, providing a healthier option for your plants. Indoor plants can benefit the most from distilled water.

Washing your face

You might want to save some of your distilled water for your evening skincare routine, as it’s a far better rinsing agent than normal tap water.

Water that contains hard-causing minerals like calcium and magnesium leave behind a scummy residue that clogs pores and leads to acne breakouts, as well as worsening skin conditions like eczema. You’re better off using distilled water, which is mineral-free and a lot kinder to skin.

Mixing with baby formula

Purified water or distilled water is recommended for infant formula for the simple fact that it’s much safer. Babies’ immune systems are still developing, which means they’re more at risk of harm from the chemicals and other contaminants found in normal drinking water. Distilled water is contaminant-free, which makes for a much safer drinking option.

Distilled vs Purified Water Compared

There is virtually no difference between distilled water and purified water that has been produced using reverse osmosis or other filtration methods. Both methods of purification effectively remove almost every single contaminant from water, producing water at its purest form.

It’s difficult to compare the actual water product, as both are so similar. Ultimately, choosing whether you’d prefer to drink distilled or purified water is a decision you’d make based on the purification method.

For some people, waiting for several hours for a water distiller to complete one distillation cycle wouldn’t be an issue. It may be that you’re prepared to wait longer for your water if it means paying far less for the distillation machine.

On the other hand, you might prefer to pay more for a reverse osmosis unit, which produces purified water immediately, on demand. The end result is exactly the same, but it can be produced more quickly.

Is purified or distilled water better?

Again, determining which type of water is better comes down to the methods used to produce water. As both reverse osmosis and distillation have their plus points and negative points, determining an ultimate favorite of the two is up to personal preference.

Reverse osmosis is a costlier process, while distillation takes longer. Ultimately, though, both methods result in a thorough purification that removes up to 99.9% of all contaminants from water. If you’re looking for clean, pure, safe drinking water for your home, you can’t go wrong with any of these water purification methods.

Note that other filtration methods, like under sink and countertop water filters, may also be considered to produce purified water. While these filters are incredibly efficient, they’re not thorough enough to remove contaminants to the same level as reverse osmosis units and water distillation machines.

If you’re comparing distillation to standard water filtration, distillation produces the cleanest and purest water.

How to tell if you need to purify your water?

It’s not always easy to tell when you need to purify your water. Water from your faucet might look clean enough, smell okay, and taste fairly normal. This is because it’s been treated beforehand at your water treatment center, where harmful contaminants, microorganisms and chemicals are reduced.

You might wonder, then, why so many people choose to purify their water, if it’s already clean enough.

The problem is that although measures have been taken to make your drinking water as safe for consumption as possible, these harmful contaminants and chemicals may remain in your water in traces. Some evidence suggests that over time, contaminants in public drinking water can cause irreversible health problems.

The easiest way to tell when you need to purify your water is to find out exactly what your water contains. You can do this by either requesting a water quality report from your local authority or testing your water with a home testing kit.

Water quality report

You should already have access to frequent water quality reports, but if you don’t think you receive them, you can get in touch with your local authority and ask to see the latest update.

Typically this will be posted on their website for easy access.

Usually, water quality reports are distributed annually, and let you know which contaminants are present in your water. They’re presented as a table, which outlines the different contaminants, by-products and chemicals that your water contains after treatment.

The report will show the MCLG, or maximum contaminant level goal – the maximum level of a contaminant that can exist safely in drinking water. You can use this to compare against the actual contaminant levels in your water. The table also lets you know exactly where a certain contaminant came from, and whether it was naturally occurring or due to industrial contamination.

Example water quality report

Home water testing

Water quality reports are informative enough, but they don’t account for the contaminants that your water might pick up on its way to your home. If you can’t remember the last time your local water pipes were changed, there’s a high chance that they’re far past their best state.

Some older water pipes contain lead, which can leach into your water in potentially harmful quantities. Bacteria and other microorganisms may also contaminate your water inside your own home’s plumbing system.

For this reason, you might want to carry out your own water testing to get a better idea of the contaminants your home’s water contains. The most popular method of doing so is by using a water testing kit.

A water testing kit comes with a number of testing strips that you use to dip into a sample of your home’s water. After a couple of seconds, the strips will turn a certain color, depending on the contaminant they’re testing for. You can then match the color of the strip to a color chart provided in the kit, which will indicate how much of a particular contaminant is in your water.

You won’t ever get the clearest or most precise reading with a water testing kit, but it’s a simple way to learn which contaminants are the most strongly present in your water, and if what you’re putting in your body is safe enough. Once you know this, you can decide whether you would benefit from purified water, and if so, which water purification method is for you.

Signs your water needs purifying

There are several signs you can look out for particularly in the water you use in your home that indicate the need for purification.

The most common of these are:

You have a limescale issue

If you currently use hard water in your water-based appliances like your kettle, you might notice that limescale builds up frequently inside these appliances despite your efforts to prevent it. This is because hard water contains calcium and magnesium minerals, which leave a sticky deposit on surfaces that’s incredibly difficult to remove.

A water distiller or purifier can resolve this issue by eliminating the limescale-causing minerals from your water, which you can then use in your home’s appliances as you please. This will help you to save money on replacement appliances and time spent cleaning them.

Wondering what the difference is between hard water vs soft water? Check out this article!

hard water stains

Your water tastes or smells unpleasant

An unpleasant taste is one of the most obvious signs that your water contains traces of contaminants. If water smells of rotten eggs, for example, it’s high in sulfur. If it’s taken on a more metallic smell, it contains a higher concentration of iron. While these elements won’t harm you when you drink them in small amounts, they can substantially worsen the taste and smell of water.

You can easily improve the taste of your water by running it through a distiller or filtration system. In the long run, drinking purified water should help you save money on bulk-buying bottled water to drink instead.

Your water doesn’t run clear

If your water is running dirty, you should contact your water supplier immediately. If it’s running clear enough, but it has a brown-ish tinge to it, it’s likely that it contains one of several contaminants.

Iron and manganese, which may leach into your water from plumbing pipes, cause water to produce an orangey-brown color, while lead may cause it to take on a darker color. You might also notice tiny particles in your water that are caused by metal deposits.

You can’t prevent these contaminants from polluting your water, but you can remove them through distillation or purification. Purified water is entirely contaminant free, and should run completely clear.

You’re scrubbing the dishes too much

Aside from limescale, hard water minerals can also prevent your soaps from lathering properly, which can make it more difficult to wash your dishes. You might find that not only does it take a long time to get your dishes clean, the hard water calcium and magnesium minerals also leave cloudy deposits on your “washed” kitchenware. This is particularly obvious on glassware.

Instead of using hard water to wash your dishes, switching to purified or distilled water will help you to get the job done faster. When the hard water-causing minerals are removed from water, you’re left with clean, soft water that lathers well with soap well and doesn’t leave deposits on your kitchenware.

You have babies or young children

If you have a baby on the way, or you already have young children in your family, drinking distilled or purified water is one of the best things for their health. Babies in particular should only drink decontaminated water, as the fluoride, lead and nitrates in normal tap water might compromise their immune systems.

Metals like iron and manganese have also been found to cause development issues in babies and young children.

Purified and distilled water are the safest drinking options for babies and children as they are completely free from harmful contaminants. Many people are unaware that babies don’t need to get their minerals from drinking water, as their formula contains all the minerals they need, so removing calcium and magnesium from water is not a health issue.

How to purify your water

Despite your drinking water being safe for consumption, you might want to take the cleanliness of your water into your own hands. There are many at-home methods of filtering your water to make it more pure, some of which are more effective than others.

As we’ve mentioned in detail earlier in this guide, the two best ways to purify your water are:

  1. Distillation
  2. Reverse osmosis filtration

It’s best to consider purchasing either a water distiller or a reverse osmosis system for your home if you want to get easy access to professionally purified water. However, if you just want to try purified water on a one-off basis before you make a more permanent purchase, you can distill it using a few components from your kitchen.

DIY Water Purification

To distill water without a water distiller, you’ll need a large pot with a lid, a collection bowl, ice cubes, and a few hours of your time to spare.

Place the collection bowl inside the large pot and partly fill the pot with water. Place the lid upside down on the pot, turn on your stove and let the water come to a boil. Once boiling, the water will start to form steam. This steam will become trapped on the underside of the inverted lid, where it’ll condense to form droplets of water. This water will drip down into the collection pot.

You can choose to add ice cubes to the top of the lid to speed the process up slightly, but you may need to wait several hours for your water to condense, depending on the size of the pot and the amount of water added.

At Home Purification Systems

Unsurprisingly, the more favored methods of water purification are those that do the hard work for us.

Reverse osmosis and countertop distillation are the best ways to produce contaminant-free drinking water. All you’ll need to do is set your unit up and perform the required maintenance from time to time, and you’ll have access to purified water whenever you want it.

Less efficient methods of purifying water are those that use just water filters, like activated carbon filters made from charcoal or coconut, which trap contaminants in water and prevent them from passing through. In many filtration systems, water passes through a number of filters, each with different pore sizes that are designed for catching the widest spread of particles. They’re effective at greatly reducing the contaminants in water, but not completely removing them.

One final method of water purification that’s sometimes used in filtration or reverse osmosis systems is a UV light. UV lights aren’t designed to remove a broad rage of contaminants on water, but are particularly efficient at removing microorganisms like bacteria and viruses.

When water passes through a UV light filter, electromagnetic energy is used to kill the harmful pathogens inside the water. It does this by altering the DNA of microorganisms and preventing them from being able to reproduce.

A UV filter is an effective method of water purification, but only when used alongside other purification techniques. As UV filters can’t remove chemicals, metals and other impurities from water, they can only assist in the water purification process.

Key takeaways

If you’ve found yourself wondering about the difference between distilled water and purified water, this guide has hopefully given you a clearer understanding of the two. Essentially, distilled water and purified water are the same thing. The only clear distinction between the water types is the way they’re produced.

Whether you decide on a water distiller or a reverse osmosis system for your home, you’ll be able to reap the same benefits no matter what.

Ultimately, regardless of the filtration model you go for, make sure that it is certified by a trusted third-party product testing and inspection organisation, like NSF International or the Water Quality Association. These independent bodies test water quality improvement systems and determine whether they comply with specific safety and performance standards. You can trust that a product with certification performs exactly how the manufacturer claims it does.

When you buy any form of filter technology, don’t forget that you’ll need to follow the user manual to ensure it stays in great condition for longest period of time.

Replacing a system’s filters and subjecting it to regular cleaning are essential for helping it to perform at its best and produce the best quality product every time. Always follow the guidelines provided by the manufacturer to know exactly how to look after your purification unit.