Carbon filters are one of the most popular and effective solutions for improving household water quality. Whether you're using a simple under-sink unit or a full whole-house filtration system, understanding how carbon filtration works can help you make informed decisions about your home's water.
What Is a Carbon Filter?
Carbon filters are made from activated carbon, typically derived from coconut shells, coal, or wood. The activation process creates a porous surface that can trap contaminants. These filters purify water primarily through two processes:
- Adsorption: Contaminants adhere to the surface of the carbon.
- Catalytic Reduction: Certain filters can chemically convert chlorine and chloramine into less harmful compounds.
Types of Carbon Filters
There are two common types of carbon filters used in water filtration:
Granular Activated Carbon (GAC):
GAC filters are composed of loose, irregularly shaped granules of activated carbon. This granular structure creates a porous matrix with a very high surface area, which allows the carbon to effectively adsorb a wide range of chemical contaminants from water, including chlorine, volatile organic compounds (VOCs), and unpleasant tastes and odors.
One of the main advantages of GAC filters is their ability to support higher flow rates, making them ideal for whole-house systems where strong water pressure is essential. Because water flows more freely through the loose media, these filters are often used in the second stage of multi-stage systems to quickly treat large volumes of water.
However, this benefit comes with a trade-off: water passes through the media more rapidly, resulting in less contact time with the carbon. This can reduce the effectiveness of adsorption for certain finer or more persistent contaminants, especially compared to carbon block filters. Therefore, GAC filters are often paired with other filtration stages to ensure complete treatment.
Carbon Block Filters:
Carbon block filters are manufactured by compressing finely ground activated carbon powder into a solid, densely packed cylindrical block. This compact form creates a highly uniform filtration surface, ensuring consistent contact between water and the carbon material.
Due to this density, water is forced to travel through a complex, tortuous path within the filter. This extended contact time allows the carbon to more effectively adsorb a wider range of contaminants, including smaller particles and more persistent chemicals that might bypass a looser filter medium.
High-quality carbon block filters are especially effective at removing chlorine, chloramines, pesticides, herbicides, and even fine particulate matter. If rated accordingly, they can also capture contaminants like lead, asbestos, and microbial cysts such as Giardia and Cryptosporidium—making them a preferred choice for households seeking advanced chemical and particulate protection.
While carbon block filters typically have a slower flow rate than GAC filters, they offer superior precision and are often used as the final stage in multi-stage systems to ensure polished, clean water.
How Carbon Filters Are Used in Whole House Filtration Systems
Carbon filters are commonly used in various stages of whole house filtration setups:
1-Stage Systems: These systems typically use a single carbon filter (either GAC or block) to target chlorine and odors, especially in municipal water supplies.
2-Stage Systems: The first stage uses a sediment filter to remove dirt, rust, and sand, while the second stage uses a carbon filter to handle chemicals, taste, and odor.
3-Stage Systems: These include a sediment filter (Stage 1), a GAC filter (Stage 2), and a carbon block filter (Stage 3). This setup is ideal for comprehensive water treatment, especially in homes with older pipes or private wells.
What Contaminants Do Carbon Filters Remove?
Carbon filters are highly effective at targeting a wide range of common water contaminants, especially those that affect taste, odor, and chemical safety. Depending on the type and quality of the carbon filter (GAC or carbon block), they can remove:
- Chlorine – Widely used in municipal water disinfection; responsible for bad taste and odor.
- Chloramine – A more stable form of chlorine that is harder to remove but can be reduced by specialized carbon filters.
- VOCs (Volatile Organic Compounds) – Harmful industrial chemicals and solvents like benzene and trichloroethylene.
- Pesticides and Herbicides – Common in agricultural runoff; includes substances like atrazine.
- Taste and Odor Compounds – Includes sulfur-like smells and earthy or musty tastes.
Note: Carbon filters do not remove bacteria, viruses, or heavy metals unless used in combination with other filtration technologies.
Benefits of Carbon Filters in Whole House Systems
Using carbon filters as part of a whole house system offers many advantages:
- Cleaner, better-tasting water from every tap
- Reduced exposure to chlorine and other chemicals in showers and laundry
- Protection for household appliances and plumbing
- Flexibility to tailor the system based on your local water quality
Peace of mind knowing your family is using safer, filtered water for all household needs
Carbon Filters from Filterway
Filterway offers a wide selection of high-performance carbon filters for whole house water filtration systems. Whether you need a single-stage solution or a full 3-stage system, Filterway’s carbon filters are designed to deliver reliable performance and long-lasting value.
Our filters are made from high-quality activated carbon sourced from coconut shells, ensuring both eco-friendliness and effective filtration. They’re compatible with standard 10” and 20” whole house systems and can be used in residential or light commercial applications.
When Should You Replace Your Carbon Filter?
To maintain effective filtration, carbon filters should generally be replaced every 3 to 6 months. Indicators that it's time to replace your filter include:
- A return of bad taste or odor in the water
- Reduced water pressure
- Recommended change intervals
Conclusion
Carbon filters play a vital role in maintaining clean, healthy water throughout your home. Whether used alone or as part of a multi-stage filtration system, choosing the right type of carbon filter and replacing it regularly ensures optimal performance. Filterway’s GAC and carbon block filters offer a trusted solution for protecting your water and your home. If you're unsure which setup is best for your water quality needs, our support team is here to help you choose the right solution.
