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Reverse Osmosis vs Carbon Filter: Which Is Better?

iSpring Countertop Filtration System

Is our water system one that we should completely trust, no questions asked? In certain areas, tap water can be worse than others. Some of the dissolved metals and other pollutants can cause harmful long- and short-term health effects.

Remember that water makes up 60% of our body weight. What is in the water can quickly impact our body. But if the water isn’t completely safe and you don’t want to pay for bottled water every day, what do you do? That is where filters come in.

Divider 3 Why Use a Filter At All?

Water treatment plants work through and send out about 44 billion gallons of water all over the U.S. every day. It works its way through miles of piping, most of which was built after World War II.

Now, decades later, there are parts of this system that are beginning to reach the end of their lifespan. Parts of them leak or leach waste into the natural water sources that we have used for so long.

Federal agencies are aware of this and have been doing their best to keep up with the replacements and repairs. However, you can do your part to protect yourself and your family as well.

Using a filter attached to the faucets inside a home has become commonplace over the last decade. They filter out harmful substances that find their way into your water.

Some areas struggle with these dissolved sediments more than others. Research which ones you need to protect yourself from the most to set up a filtration system that suits your needs.

Common chemicals, metals, and other substances found in trace amounts in tap water:

  • Aluminum
  • Arsenic
  • Barium
  • Cadmium
  • Calcium
  • Chlorine
  • Copper
  • Lead
  • Magnesium
  • Mercury
  • Nitrates
  • Radium
  • Sulfate
  • Synthetic Organic Compounds (SOCs)
  • Volatile Organic Compounds (VOCs)

The EPA monitors most of these. However, a growing number of researchers and scientists believe that they allow for more of them in water than is healthy.

Having a household filtration system not helps remove these, but it also eliminates substances that affect the taste and smell of water. With a quality filter, you turn on the tap and get a glass of water that tastes even better than typical distilled water.

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Reverse Osmosis Overview

Reverse Osmosis
Reverse Osmosis Filter System, Credit: APEC, Amazon

Reverse osmosis is a process commonly found in the anatomy in natural creatures. Scientists used it to develop a humanmade system that uses membrane technology.

Water flows through the tap until it reaches the semi-permeable membrane. There is a pre-filter that takes out larger particles and sediment pieces. Then, a pre-carbon block filtration system removes chlorine, one of the most common chemicals in tap water, and several others.

The water pushes against the membrane itself, and the water separates from the other, small elements that find themselves unable to pass through. Finally, it is the post-filter that works to improve the taste of the water and remove odors.

Reverse osmosis removes most of the major players in the list above. It is typically the system that restaurants use. It removes anywhere from 95-99% of the harmful substances in your water.

Unfortunately, the process isn’t perfect. It doesn’t allow all the water to pass through all the time and can create water wastage, which is vital to avoid in some areas. It does this because it uses anywhere from 50-70% of the flowing tap water to flush out the membrane. This water then gets flushed away by the system.

Although it removes most chemicals, it is not the best at straining out the VOCs in the water. Since the membrane gets exposed to so many sediments and particles, if you don’t clean it frequently, bacteria are prone to make its home on the surface.

Due to its overall complexity and effectiveness, reverse osmosis is often the most expensive way to clean water.


  • Better at removing dissolved salts
  • Removes heavy metals, asbestos, and most pollutants
  • Creates water waste
  • Might not remove VOCs
  • More expensive

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Carbon Filter Overview

iSpring CKC1C Countertop Drinking Water Filtration System

Carbon filtration has been in use for centuries. Many historians believe that the ancient Egyptians first invented it with the discovery of the properties of charcoal. They found that it helped improve the taste of the water and keep it fresher for a longer time.

Nowadays, carbon filters are produced by heating carbonaceous material. These are anything from coconut shells to coal. They place them in chambers filled with nitrogen or argon while bringing it to very high temperatures.

Activated carbon is one of the materials that is used for carbon filters because it is incredibly porous. It works by attracting chemicals toward it at a molecular level. It absorbs these and allows only the clean water through the entire way.

They work best by absorbing unwanted chemicals, such as chlorine and mercury. It is also one of the only filter types that work to remove chemical pesticides and herbicides safely. However, it does not help much to remove heavy metals from the water because they cannot be attracted the same way.


  • Cost-effective option
  • It still removes high levels of chlorine, sediment, and VOCs
  • Typically does not remove heavy metals

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The Bottom Line

When you consider what filtration system you want to use in your home, it shouldn’t come down to only one filter. A combination of the two, reverse osmosis and carbon filters, will ensure the most amount of harmful material being stripped from the water.

Research what pollutants and harmful substances are most commonly present in higher amounts in your area.  Knowing this will help you figure out your home’s needs and allow you to drink safe water that properly supports you and your family.


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