Why Should You Change Your Refrigerator Water Filter Every Six Months?

The life of refrigerator water filters is dependent upon the volume of contaminants in the water as well as the amount of use of the filter. Well water is more likely to contain contaminants not found in publicly treated water and may need more frequent filter changes. As a rule of thumb, the filter should be changed as specified by the manufacturer or at least every six months.
Carbon is the primary substance used in water filtration methods because carbon has the potential to absorb many of the chemicals found in water. Most refrigerator water filters, which meet NSF/ANSI 42 certification standards, use granular activated carbon (GAC) to attract chemicals and impurities responsible for bad taste and odor, such as those that are a by-product of chlorine. These filters are not capable, however, to rid water of more dangerous, health-threatening contaminants. The method by which water is channeled through GAC filters does not allow sufficient time to complete the absorption of such substances. Various bacteria are formed, trapped and allowed to multiply, which further contaminates water processed by the filters. Carbon is not capable to absorb heavy metals, such as lead. GAC filters may trap some heavy metals and sediments, but allow others to filter through to the output water. Failure to change the water filter, every six months, allows unabsorbed water contaminants and newly formed bacteria to saturate the filter, forcing the filter to leak contaminants back into processed water. The water output may contain more contaminants than the filter was intended to remove in the first place.
Technology has lead to the development of more absorbent carbon-based filters, solid carbon block filters. These filters include solid blocks of carbon to absorb contaminants from water. Water takes longer to strain through carbon blocks than it does carbon granules, so that carbon blocks provide sufficient time for the absorption of more health-threatening containments. While carbon block filters are capable to absorb toxics, pesticides, TTHM's and other contaminants, they cannot absorb heavy metals or contaminants that are by-products of agricultural fertilization, such as nitrates or sulfides. The composition of carbon blocks allows them to restrain heavy metals and bacteria away from output water, however, nitrates and sulfides are not filtered. Even so, carbon block filters are sufficient to meet NSF/ANSI 53 certification standards. Failure to change carbon block filters, every six months, allows contaminants to saturate the filter, forcing the filter to leak contaminants into the processed water. When sediments are not removed from water, those sediments buildup and corrode filter fittings and water fixtures, causing them to leak. This type of damage to filters and fixtures may cause the output water to contain more contaminants than the water input to the filter. Failure to change the filters might also reduce the water pressure, within the filtering system, forcing it to be ineffective.
Some refrigerator water filters may include fiber water filters. These filters are made of tightly wrapped fibers of rayon or spun cellulose, which trap rust, lead and other sediments found in water. When used alone, these filters are ineffective in reducing any chemical or health-threatening contaminants. Fiber filters are best suited for use with other types of filters to reduce the concentration of sediments. They should be replaced, every six months, to avoid a build-up of sediments that would force the filter to leak the contaminants back into the processed water.