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Gravity Carbon Block Filters vs Granular Activated Carbon - Comparing Water Filtration Methods

Comparing gravity carbon block filters and granular activated carbon water filtration methods. Learn the pros and cons of each technology and which works best for treating water in Tampa Bay, FL homes.
Comparing gravity carbon block filters and granular activated carbon water filtration methods. Learn the pros and cons of each technology and which works best for treating water in Tampa Bay, FL homes.

When it comes to filtering water for home use, two of the most common methods are gravity carbon block filters and granular activated carbon (GAC) filters. Both use activated carbon to absorb contaminants, but there are some key differences between the two technologies.

In the Tampa Bay area, water quality can vary depending on your location and water source. Many homeowners use city water from the Floridan Aquifer, while others rely on private wells tapping into the aquifer. Issues like hardness, iron, manganese, sulfides, and bacterial contamination are common. An effective filtration system is crucial for improving water aesthetics, appliances, and your family's health.

How Do Carbon Block Filters Work?

Carbon block filters use a solid carbon block medium made from powdered activated carbon that is compressed under high pressure. This creates a durable, porous block that water passes through.

As water flows through the micropores of the carbon block, contaminants are trapped and adsorbed onto the surface of the carbon. This removes chemicals, sediment, metals, microorganisms, and improves tastes and odors.

Carbon blocks are incredibly dense and allow for superior contaminant removal compared to loose granular activated carbon. They also last longer before needing replacement.

AquaBlue Whole House Filter System uses multi-stage carbon block filtration to remove a wide range of contaminants from all the water in your home.

Benefits of Carbon Block Filters

  • Very dense for excellent contaminant reduction

  • Long filter life

  • Maintains flow rate longer than GAC

  • Smaller filter size required

  • Low pressure drop through the filter

  • Can customize block composition for specific contaminant removal

How Does Granular Activated Carbon Filtration Work?

GAC filters are filled with loose granular activated carbon particles that water flows through. The carbon particles provide a huge amount of surface area for adsorption of contaminants.

GAC is very porous, which allows for rapid adsorption kinetics. Water can flow through the gaps between carbon particles easily. Particles are sized according to the application - larger particle sizes allow for higher flow rates while smaller sizes increase dwell time and removal efficiency.

AquaCarbonGuard Catalytic Carbon Filter uses a specialized high-activity catalytic carbon media optimized for iron, manganese, and hydrogen sulfide removal.

Benefits of Granular Activated Carbon

  • Excellent adsorption capacity

  • Rapid adsorption kinetics

  • Allows higher flow rates

  • Media can be easily replaced

  • Wide selection of carbon types

  • Economical compared to solid block

Comparing Contaminant Removal Capabilities

Both carbon block and GAC filters are highly effective at removing a wide range of contaminants through adsorption. However, there are some differences in their capabilities and limitations:

Chlorine Removal

  • Carbon block filters excel at reducing chlorine and chloramines due to their very high surface area and pore distribution. GAC is less effective.

VOC and Chemical Removal

  • Carbon blocks adsorb VOCs, pesticides, herbicides, pharmaceuticals, and other trace organics better than GAC filters. Their very dense structure provides increased removal.

Heavy Metal Removal

  • GAC has an advantage over carbon block for removing certain heavy metals like lead and mercury that adsorb easier to the loose particles. The HydroClear Ozone Generator enhances metal oxidation for more complete removal.

Sediment Filtration

  • Carbon blocks are better for filtering out suspended solids and sediments larger than 1-5 microns in size. GAC is ineffective for sediment.

Microorganism Removal

  • Small bacteria and viruses can become lodged in the micropores of carbon block filters. AquaGuard UV SYSTEM provides superior bacteria inactivation.

Taste and Odor Reduction

  • Both GAC and block filters adsorb contaminants that cause unpleasant tastes and odors very well. Carbon block may have an edge due to the density and pore structure.

Typical Applications and Uses

Gravity carbon block and GAC filters lend themselves to certain applications and scenarios based on their characteristics:

Carbon Block Filters

  • Whole house filtration - AquaBlue

  • Point-of-use drinking water - AquaRevive RO

  • Countertop water pitchers

  • Refrigerator filters

  • Shower filters

  • RV and marine systems

Granular Activated Carbon

WellFusion whole house systems often combine carbon block and GAC filters for comprehensive water treatment.

Key Differences Summary

Gravity Carbon Block

Granular Activated Carbon

Solid porous carbon block

Loose granular carbon particles

Very high density

Porous allowing water flow

Excellent removal of chlorine and organics

Rapid adsorption kinetics

Higher contaminant reduction

Requires frequent backwashing

Longer filter life

Media can be easily replaced

Used primarily for residential filtration

Used more for industrial and municipal systems

Choosing the Right Filtration System

Gravity carbon block and granular carbon both utilize the adsorptive power of activated carbon to remove contaminants from water. Which method works best depends on the specific water quality issues that need addressing.

Most residential water filter systems in Tampa Bay use a combination of filtration technologies like carbon block, UV disinfection, and reverse osmosis for comprehensive water treatment. Systems are tailored to handle contaminants in your local water supply.

Professional water analysis is the best way to determine if your water contains any aesthetic, health-related, or appliance-damaging contaminants. This allows selection of the right treatment methods for your needs.

Aqua-Wise Water Treatment Solutions offers complete testing, analysis, and installation of advanced water filtration systems for homes and businesses throughout the area. Take advantage of our expertise and schedule a free water test from our certified technicians.

Call to Action: Discounts, Promotions, and Financing Options

For a limited time, Aqua-Wise is offering exclusive discounts on whole house and point-of-use water filtration systems. We also provide flexible financing options to help make clean, healthy water affordable for Tampa Bay area homeowners. Schedule Your FREE Water Test Today: 727-236-7161.


  • EPA - Drinking Water Treatability Database: Granular Activated Carbon

  • CDC - Guide to Water Filters

  • Water Quality Association - Activated Carbon Treatment 101

  • Water Research Foundation - Comparison of GAC and Carbon Block Filters for Pesticide Removal


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