Chloramines are a blend of chlorine and ammonia, it is used to maintain residual chlorine levels in the drinking water distribution system since it is more stable than free chlorine alone.
Since TFC RO membranes are damaged by even slight amounts of chlorine, to safely remove chloramines you need two things, carbon for the chlorine portion before the RO membrane and since RO membranes are not particularly effective at all forms of ammonia (ammonia, nitrates and nitrires) good DI resin for the ammonia portion after the membrane. Many will tell you you need special catalytic carbons and it removes everything but that simly is not true. The carbon does not remove the ammonia which is the harder to remove piece. Any of todays modern extruded carbon blocks in a 1 micron or smaller size is more than sufficient for the chlorine in chloramines at normal residual levels and a good 20 oz. vertical full size mixed bed nuclear grade DI canister and cartridge is almost manditory and is by far the more important piece of the puzzle. You don't want nor need two carbons, granular carbons or anything else, just one 1 micron or smaller carbon block protected by a 1 micron or smaller sediment filter so its billions of tiny microscopic pores where the chlorine is adsorbed do not get fouled or plugged.
