carbon blocks

Planning to get a RO/DI unit What are the difference of UDF, CTO carbon block etc etc Is activated carbon allowed in RO/DI for salt water ?

Residual chlorine (no chloramines) in the water mains where I live in Italy is between 0,03 and 0,05 ppm. Do I need a very good 1 mcr carbon block, or can I just get a cheap 10 or 5 mcr carbon block and replace it once a year? Is it recommended to test for chlorine after the carbon blocks, or...

Residual chlorine (no chloramines, only chlorine and chlorine dioxide) in the water mains where I live in Italy is between 0,03 and 0,05 ppm. Do I need a very good 1 mcr carbon block, or can I just get a cheap 10 or 5 mcr carbon block and replace it once a year? Is it recommended to test for...