So just got my RO drinking water unit and installed it, 320ppm tds at tap in, after flushing system for an hour i had 22ppm at drinking tap out. I checked my city's annual water reports and they list the use of Chloramine as primary disinfectant, do i need a special carbon stage? Stages are Sediment - Gac - Cto - RO - storage tank -Post Carbon , I also ran a Tee after RO to install a check valve for DI ,waiting on amazon to deliver DI cartridge and valves so no readings there yet. I have good water pressure and unit has a booster pump, got unit cheap on Ebay with the idea of upgrading stages as needed, just want to make sure I get the correct filters for my water.