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What is a carbon water filter (What do they do)

Chlorine is a common contaminant found in-home water because city municipal use chlorine and chloramine chemical to treat water. It’s common to have chlorine leftover that affects the smell and taste of your water. Using a carbon water filter helps remove the chlorine taste and odor in the tap water so you have pure and refreshing water.

carbon water filter

A carbon water filter is water filtration media used for removing chlorine taste. Water treatment systems such as reverse osmosis, water filter pitcher, whole house water filter, faucet, shower filter, refrigerator filter, backpacking filter, and more utilize a carbon water filter

Carbon filters are made from organic raw materials that are high in carbon. Such raw material includes coal, wood-based, or coconut shell. In water filtration, we don’t coal because of arsenic that comes through mining so we use coconut shell to make carbon filter because is renewable and good for filtration.

The raw material is heated in absence of oxygen to increase the surface area of carbon.  Also, heating the filter gives carbon more capacity to hold contaminants. That’s why it is also known as a charcoal filter.

Carbon filter has a large surface area, therefore, has more capacity to hold impurities.

How does carbon water filter work

A carbon water filter removes contaminants using the adsorption method. The filter soaks/absorbs contaminants particles in water like a sponge. The particles stick in the filter and clean water pass through.

Note the sponge absorbs with B but carbon adsorbs with d. The sponge absorbs water when you squeeze it using your hand it releases water but carbon soaks contaminants when you squeeze does not release so contaminants remain in it

What to check when buying a carbon filter

  • Pore size

The filter pore size is measured in microns. If the micron is small the better because the finer the filtration. The range is from 0.5 up to 50 micron

  • Flow rate

Less flow rate or low water pressure gives more time water contact with the surface of the filter and more contaminants the filter soaks.

The more contact time the filter has with the carbon filter surface, the more efficient filtration meaning more contaminants the filter will soak.

  • Types of carbon filter

The carbon water filter is available in two types backwashing filter and cartridge filter style

Cartridge filter that includes Granular Activated Carbon filter (GAC), Activated carbon block (ACB), catalytic carbon filter, and coated carbon filter

  1. Granular Activated Carbon filter (GAC)

Granular Activated Carbon filter focused on capturing chemical contaminants such as chlorine, radon, and VOCs (volatile organic compounds).

It also removes cloudiness, offensive odors, colors, and unpleasant tastes.

After using the GAC filter for sometimes the ability to remove the chemical is used up and require to be changed to work effectively

GAC water filter is used mostly for polishing but can be used as a pre-filter

  1. Activated carbon block (ACB)

Activated Carbon Block filter removes chlorine, VOCs (volatile organic compounds) including insecticides and pesticides.

It also removes chemicals causing bad tastes and odors

The Activated Carbon Block filter focuses on the taste and drinkability of your water and removing chemicals.

  1. Catalytic carbon water filter

Is a carbon block that has a special coating that enhances the adsorption process making it good to remove chloramine. Nowadays municipalities have started to use chloramine to treat water. Chloramine is a chlorine and ammonia compound. It takes a lot of time for activated and granular activated carbon to remove chloramine so catalytic carbon water filters help remove chloramine

Coated carbon water filter

Is a carbon block that has a special coating/blend that helps remove sediment, arsenic, dissolved inorganic compound, and lead.

We know carbon water filters are good for removing volatile organic compounds such as chlorine and chemicals (herbicides and pesticides).

If you want to remove sediment, arsenic, dissolved inorganic compounds, and lead using a carbon filter you must blend or coat with something else. Some companies call it impregnated carbon filter

  1. Backwashing carbon filter

Backwashing carbon filter uses a tank to store filtering media. Contaminated water passes through the media inside the tank that removes them.

After treating water for some time the system automatically cleans itself through a process called backwashing.

During the backwashing process the contaminants the media have collected flush away leaving you with clean media to treat water.

Best Backwashing carbon filter

Oceanic Whole House Carbon Water Filtration Backwash System

Carbon tank Filter system

Watch the video to understand the difference between a Carbon backwash filter vs cartridge

Granular activated carbonCarbon block filter
Loose granules of carbon/ grounded carboncompressed block of carbon
higher flow ratelower flow rate
Post and pre-filterPrefilter
Improve taste and odor by removing chlorineFilter sediment, chlorine, pesticides, heavy metals and more
adsorbAdsord and filter

What contaminants does the carbon filter remove?

Carbon takes care of contaminants that are organic in nature such as

  • Volatile organic compounds
  • Chlorine, taste, and odor
  • Perfluorooctanesulfonic acid (PFOS)-used to make fabric, carpet, paper packaging for food and furniture
  • Pharmaceuticals – a chemical found in drugs and can get into water through improper disposal of drug
  • Pesticides and herbicides

Carbon is not good at removing arsenic, dissolved inorganic compounds, and lead it requires special material blended with carbon to remove lead

How often are you supposed to change the carbon filter?

Changing the carbon filter depends on the contaminant’s level and water use. If contaminants level and water usage are low the filter can last for long but if the case is vice versa you require frequent change.

It is recommended to replace the carbon filter every six months or 1 year. If you wait for long the filter pores will become full causing the collected particles to break from the carbon and eventually flow in your water supply.

Where to install a carbon filter

A carbon water filter can be installed at the point of entry and point of use

A point of entry is installed to treat water for the whole house. They are installed at the main water supply and treats all water entering your whole house.

The Point of use is installed before you drink, use for cooking, or bathing.

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