A TDS meter is provided to determine the exact life span of the filter itself. Put these periodically in the filtered water. You can read in the manual how the TDS meter indicates when the filter is ready for replacement.
It is only possible to indicate the durability of the filter. This is because the durability depends on the pollution in the tap water and the amount of water filtered per day. The amount of pollution is different everywhere. For example, this not only depends on the filtration by the water companies but also on the quality of (indoor) water pipes.
Would you first like to get an indication of the number of liters of water that can be filtered? The first thing you have to do is order a TDS meter and provide your measurement via the contact form.