Filter cartridge Big Blue - 20 inch UDF GAC filter. We only stock high quality products.

Also available in a 6 pack and a 10 pack. Filters should be replaced from 3 months and up depending on incoming water quality

Granular Activated Carbon Filter

Granular Activated Carbon, also known as a GAC/UDF Filter, is carbon that has been treated with oxygen to make it porous. It has also been broken up into granules to further increase the surface area available for chemical bonding to occur. As water passes through the filter, organic materials and chlorine effectively bond with the carbon molecules, removing them from the water.

The effectiveness of Granular Activated Carbon (GAC) filters depends on flow rate and contact time with the water. If the flow rate is very high, efficiency can drop to as low as 0%, but at a slower flow rate, efficiency can exceed that of various other carbon forms.

Granular Activated Carbon is used to absorb natural organic compounds and synthetic organic chemicals that affect the colour, taste, and odour of drinking water.

The GAC filter may vary in colour and design depending on the manufacturer, though the internal carbon media remains the same.