There are two parts to the filter elements; the ceramic shell, and the granulated carbon filling. Cleaning of the ceramic shell is what wears out the ceramic portion of the filter. Over time, particulates and bacteria clog the microscopic pores of the ceramic, slowing down the flow rate. Occasional cleaning with a small brush or the enclosed green scrub pad will restore the original flow rates. Eventually, cleaning of the ceramic will wear the walls down, making them thinner. When the attached gauge can fit over the diameter of the ceramic, you know it is time to replace the element. Our ceramic formulation is very hard and will endure many cleanings, perhaps over 200 if moderate care is taken and light pressure is used. In normal usage this equates to thousands of gallons of water that can be filtered.
The inner carbon filter works by adsorbing and/or reducing certain chemicals, and has a finite lifetime based on the concentration of the compounds being reduced. Generally speaking, the carbon capacity should exceed the life of the ceramic portion of the filter when processing water from most sources. Annual replacement of cartridges should guarantee sufficient carbon capacity for maximum protection. Please note that should the carbon become exhausted, that the elements are still fully effective for the removal of protozoic cysts and harmful bacteria, provided the remaining ceramic wall thickness still has useful life.