Large capacity units installed under sinks are more efficient. Generally, carbon filters should only be used with waterthat has already been disinfected. The amount and type of activated carbon afiltercontainswill influence its effectiveness. Systems with large amounts of activated carbon are the most effective. GAC particles are comprised of an intricate system of microscopic tunnels that provide a huge surface area.
Activated carbon is also extremely absorptive.
Many contaminants stick to the carbon when they contact it. The rate that water flows within the filter is also important. If the flows are too rapid, there is little opportunity for contaminants in the waterto contact the carbon. Systemsthat allow water to slowly trickle through the units provide the longest contact times and increase pollutant removal. Because faucetmounted units often have too little contact time, they are not as effective as many under the sink filters.