Dechlorinating water for Quantum Total

[vegetalmatter]

About two month ago I received my order of Quantum Total and applied a treatment. smelly stuff. Since then I've been dabbling in aquariums and received advice to not rinse aquarium filter sponges with water straight from the tap because the chlorine will kill nitrifying bacteria. Just yesterday I skimmed the label on the Quantum bottle and what do you know, they advise that I use dechlorinated water only. Oops. Would a standard aquarium dechlorinator like Seachem Prime be safe for orchids? The city of Austin uses chloramine in our water supply and from the advice of fish people, I've been using twice the amount of Prime to take care of that when using tap water for my aquarium. What are orchid people using to dechlorinate water?

ps: I do use RO water for orchids, but I've been told by aquarium folks that some RO systems don't get rid of chlorine/chloramine. thoughts?