How long a filter will last can be estimated based on the TDS value of your tap water and your water consumption. The TDS value indicates how many organic dissolved elements are in your tap water. You can measure this using a TDS meter.
A filter can last longer if you have a low amount of dissolved solids (TDS) in your water.
Using the table below you can estimate for yourself how much water can be filtered per filter. A filter should be replaced at a value of 006 PPM or higher. The other indication of a saturated filter is when the smell and/or taste of the filtered water changes.