High Chloramine content of tap water can damage TFC membranes but within most of Europe water standards are high and we use very little Chloramine compared to some areas of the United states for example.

The single carbon block pre filter is generally more than enough unless local tap water is very high in Chloramine, the pre filter should be swapped out every 3-6 months.
We would advise monitoring the post membrane TDS in an ongoing manner as this will highlight the health of the membrane and indicate any biological or chemical fouling over
time.