R O systems are not designed specifically to remove chloramines. They can do so but you must pay more $$$ as it requires a more sensitive filter. Do the vitamin C trick and it neutralises Clorine and Cloramine almost instantly. Aquarium conditioning products also work but why pay more. The advantage of using aquarium products is that both chlorine and ammonia are neutralised (ammonia is like poison to fish). Ammonia in small amounts is perfectly fine for plants when we are talking 1 or 2 PPM, which is all that would remain from from the cheap vitamin c dechloramination method. It's also worth noting that if you grow in soil that has ample microbial life the chloramines will be neutralised with minimal damage to the soil. Be sure to leave your water out to evaporate the chlorine first though so only the chloramines remain.