if you have no minerals, nad your parameters are all good, yes, it will soon go away, but your ammonia-nitrites-sitrates-phosphates must all be ZERO(for your tanks health too) and it will all pass
and RO stands for reverse osmosis, it is a method of treating water, where they actaully squeeze all of the impurities out of it, this actually is not sw slang, but water industries in general, but i think it is on the slang post anyway