Does Not Eliminate All Contaminants
Although charcoal is a relatively effective filter medium, it’s not perfect. Like other filtration media, it’s possible for small debris and contaminants to pass through a charcoal filter and end up in drinking water. In addition, most of these filters cannot eliminate dissolved solids, hardness or heavy metals. Charcoal filters work best when used in combination with a chemical treatment process to remove any remaining impurities filtering leaves behind. Look for a charcoal filter that offers antibacterial protection developed to eliminate organisms present in unfiltered water.
Charcoal filters last a limited amount of time before they need replacing. On average, charcoal filters last two to three months. Filters used beyond this time have limited effectiveness. Furthermore, these filters can collect bacteria if left over time, which can transfer to the water when contact is made. The Canada Mortgage and Housing Corporation recommends consumers using this filter to thoroughly rinse it daily to prevent bacteria buildup.
Proper installation is needed to ensure the filter works effectively. If it’s not correctly installed, the filter can actually release impurities back into the water. An improperly installed filter also fosters bacteria growth. According to the Canada Mortgage and Housing Corporation, studies indicate the bacteria present in water passing through an improperly installed filter are up to 2,000 times higher than levels found in unfiltered water. Charcoal Water Filters, a charcoal water filter information website, found consumers who purchased certain under-sink water filters (for example, Culligan US-600 3/8 inch) and water filtration systems (for example, 3M Filtrete 3UP-PS01 Under Sink Professional) found them difficult to install. In addition, water filtration systems using charcoal filters can slow water flow.