In a nutshell......
The elements that come out of solution as scale inside your coffee machine, pass straight through "regular" particle filters because they are not particles......they are "in solution".
There are two ways of attacking this:
a) use a "water softener" which is a device that takes the elements out of the water before the water goes into your machine and
b) use a "water filter" that releases a scale inhibiting substance that stops the elements coming out of solution as scale in the machine and/or sticking to the insides of the machine.
If you want to know if your water filter has scale inhibiting properies, you will have to make enquiries with the supplier / importer / manufacturer of your filter.
Hope that helps.
very first CS site sponsor*