What is the Difference Between Carbon Filters and Carbon Block Filters?

In a carbon block filter, the carbon is crushed to a fine powder and compressed to form a solid block. A granular carbon filter, on the other hand, is made up of loose carbon granules. The compact nature of solid carbon provides better purification, while the more flexible nature of the GAC (Granular Activated Carbon) offers a higher flow rate. Carbon block filters are created by grinding activated carbon into a fine powder, which is then mixed with a food-grade binder and heated to activate and compress it into a solid block.

This process produces a much finer particle size, resulting in a larger surface area for contaminants to adhere to. Carbon block filters are ideal for high pressures of 60 psi or more, where a lower flow rate is acceptable. To control the flow rate, a flow limiter, wider diameter water lines, or a pump can be used.

The Benefits of Carbon Block Filters

Carbon block filters are highly effective at filtering out a variety of contaminants, including very small particles or contaminants.

Generally, water will flow more slowly during this filtration stage due to the compact nature of compressed carbon. If the carbon is activated, the catalytic activated carbon (more reactive) chemically alters the chlorine molecules, converting them to chloride (the ionically charged form of chlorine). To remove any trace of these chemicals and restore drinking water to a safe and healthy state, carbon filters are used to improve the taste and smell of the water.

The Benefits of Granular Activated Carbon (GAC) Filters

GAC (Granular Activated Carbon) filters are often used as “polishing filters” in the water filtration process and are very effective in improving the taste and smell of drinking water.

The elements and compounds that then bind to the carbon atoms are removed, and all of the carbon's binding sites are “free” to bind to the incoming molecules and atoms. Coconut is the type of carbon most used in water filters today, as it is effective in eliminating bad flavors, odors, volatile organic compounds, chlorine, pesticides and more. Coconut water filters are made from coconut shell charcoal that has been vacuum-heated in a laboratory and cleaned.

What Can Carbon Filters Remove?

In general, organic compounds and volatile organic compounds, THMs (Trihalomethanes), pesticides, herbicides, and chlorine can be removed using both types of activated carbon filters.

However, it takes time for water to flow through compressed carbon block filters, which can reduce the flow rate. Usually, there will be a 1 or 5 micron sediment filter, 1 to 2 carbon blocks, and a 1 to 10 micron GAC filter in any given water filtration system; possibly even a UV light (best for well water) and a reverse osmosis membrane that removes it. In fact, just about every type of water filter system uses carbon filtration in some way.