Reverse Osmosis vs Filtered Water: Which Is Better + Differences

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What’s the difference between reverse osmosis and filtered water?

And which is the better option?

Let’s find out!

Key Takeaways

  • Reverse osmosis water is a type of purified water that is produced by passing feed water through a reverse osmosis membrane. The process is highly effective and removes most impurities.
  • Filtered water can be obtained in various ways – by sediment filtration, carbon filtration, ion exchange filtration, etc. These filtration types all target different contaminants and provide different levels of water purity.
  • In general, reverse osmosis water is much purer than regularly filtered water.

Filtered Water vs Reverse Osmosis Water – Which Is Better?

So, filtered water vs reverse osmosis, which is the better option?

Well, filtered water and reverse osmosis water both fall under the broad umbrella of purified water. They can have many similarities, but they can also be quite different.

The question is, what type of filtered water do you have? Because filtered water is any water that has been treated by passing it through a water filter. That could be a sediment filter to remove coarse dirt, a carbon filter to remove organic chemicals, or an ion exchange filter to remove salts and metals.

Reverse osmosis water, on the other hand, is water purified by passing it through a reverse osmosis membrane. This process is highly effective and removes most contaminants and impurities providing water of exceptional purity.

blue reverse osmosis membrane

Bottom line: Reverse osmosis water is often much purer than regular filtered water and preferred for drinking – although this highly depends on how the filtered water was processed.

What Is RO Water?

Reverse osmosis water is produced by an RO system. The system works by passing water through a semipermeable reverse osmosis membrane with very small pores that prevent contaminants from passing through. Almost only clean water makes it to the other sites.

The reverse osmosis process is thorough, most contaminants and foreign bodies are removed from the water completely, making RO water very pure and safe for drinking.

You can get RO water by installing a reverse osmosis system at home or buying bottled RO water from one of the many available brands.

What Is Filtered Water?

As mentioned earlier, filtered water is water that has been treated by filtration. Filtration involves passing water through a filter medium to remove unwanted contaminants.

Different types of contamination can be removed depending on the type of filter media involved, such as:

  • Carbon filters are most commonly found in homes today, and they remove contaminants like chlorine, volatile organic compounds (VOCs), pesticides, and even some heavy metals.
  • Sediment filters remove sand, silt, dust, rust flakes, and other dirt.
  • Ion exchange resin can be used to target heavy metals and salts.

Is RO Water the Same as Filtered Water?

No, RO water is not the same as filtered water. There are different types of filtered water, depending on the filter media used. But RO water is always obtained from a reverse osmosis process.

Types of Water Filtration

Below are three types of water filtration explained in a bit more detail. Keep in mind that there are many more methods available.

Sediment Filtration

Sediment filtration is a process where solid particles are removed from water by passing it through a sieve-like filter medium.

Sediment filters are made of porous materials like polypropylene or ceramic that allow clean water to pass through while blocking larger contaminants. They can remove suspended particles in water like sand, rust, and other debris.

Although it’s a filtration process on its own, sediment filtration is often used as pre-treatment, It protects the other filter stages from dealing with too many suspended particles that could cause clogging.

Carbon Filtration

Carbon filtration is a process that utilizes activated carbon to adsorb impurities from water.

Activated carbon is a type of carbon that has been treated to possess a high surface area with adsorbent properties.

Activated carbon filtration is widely used in homes and offices. It filters many contaminants, including chlorine and other water disinfectants, volatile organic compounds, pesticides and herbicides, pharmaceuticals, and certain heavy metals like lead and mercury.

Filtering water with activated carbon usually leads to much better taste and odor. Another pro: Carbon filters are very affordable.

Granular Activated Carbon

Ion Exchange

Ion exchange removes dissolved ions from water.

It works by passing water through a resin bed (the resin bed can be positively or negatively charged, depending on the charge of the target contaminant).The resin bed attracts the ions in water, and they stick to its surface, exchanging places with the ions that were on the resin.

It’s a method that can be used to remove all kinds of metals, salts, and certain chemicals.

The Pros and Cons of Filtered Water

Pro: Cleaner Drinking Water

Filtering your water means it’s probably less contaminated with sediments, chemicals, or microbes that could be potentially harmful.

Pro: Better Tasting Water

Filtered water (from carbon filtration) is free from chlorine taste and odor. Filtering your water before drinking can make it much more enjoyable.

Pro: Saves Money

In the long run, filtering your own water is a lot cheaper than buying bottled water. Filtration methods like carbon filtration are cost-effective and very efficient.

Pro: Eco-Friendly

Drinking filtered water is great for the environment. Instead of buying bottled water and contributing to plastic waste, you can filter your water and limit how many single-use bottles go to waste.

Pro: Convenience

Access to filtered water 24/7 is a lot more convenient than running to the store because you ran out of bottled water. You’ll also drink water more freely and not worry about how many bottles of water you have left.

Con: Initial Cost

Some water filter systems have high initial and subsequent maintenance costs that may be unaffordable for many people.

However, there are always cheaper water filter alternatives to go for. For example, you can try a simple water filter pitcher.

Con: False Sense of Security

Drinking filtered water may cause you to believe it’s completely safe, even when it isn’t.

For instance, some water filters may be unable to remove volatile organic compounds and other contaminants like PFAS.

The Pros and Cons of Reverse Osmosis Water

Pro: Safe Drinking Water

Reverse osmosis protects you from consuming almost any water contaminants. The RO process is highly effective.

Pro: Better Water Taste

RO water is free from contaminants that are responsible for weird tastes and smells in water.

Pro: You Drink More Water

Nothing encourages drinking water like a steady supply of clean, great-tasting H2O.

Reverse osmosis water tastes superb and can spur you to improve your water-drinking habits. You may also be motivated to stay off carbonated drinks since RO water is so refreshing.

Con: Water Wastage

The reverse osmosis process wastes a lot of water in many cases. The average RO system wastes about four gallons of water for every gallon of filtered. This is a major downside.

However, installing pumps in your system can help reduce the amount of waste water produced by as much as 90%.

Con: Loss of Useful Minerals

Reverse osmosis is thorough. It removes all impurities in water, including those that may benefit your health. This includes minerals like calcium.

Con: Reduced Water pH

RO water is often mildly acidic. You’ll need to talk to your doctor if you have gastric ulcers or other conditions that may make you sensitive to it.

pH scale

Differences Between RO and Filtered Water

The difference between RO water and filtered water is quite straightforward:

RO water is water that has been purified with a reverse osmosis process. In comparison, filtered water is produced through water filtration processes like sediment filtration, ion exchange, or carbon filtration. Generally speaking, RO water is considered more thoroughly purified than regular filtered water.

How Does a Reverse Osmosis System Work and What Does It Remove?

Aside from the various pre and post-filter stages, reverse osmosis systems work by forcing pressurized water through an ultra-fine semipermeable membrane. The RO membrane has very tiny pores that reject contaminants larger than 0.0001 microns.

This means only pure water molecules can pass through the membrane. The filtered water is then kept in a storage tank for future use, and the rejected contaminants on the membrane are flushed out of and sent down the drain as waste water.

RO systems are either point-of-use (POU) systems which filter water at a single point in the household or point-of-entry (POE) systems which filter all of the water coming into the home.

Reverse osmosis systems remove contaminants like:

  • Chlorine and chloramine
  • Sediment, rust, silt, and dirt
  • VOCs
  • Pesticides and herbicides
  • Disinfection byproducts
  • Metals like lead, arsenic, chromium, aluminum, and copper
  • Bacteria, cysts, viruses
  • Salts and minerals
  • Radioactive elements
  • Asbestos

If you have any questions about filtered water vs reverse osmosis please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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