why will chlorine react in a water that is very clear but chemical has iron content?which turns it brownish.and what is the fastest why to remedy the water?

Answer 1

Perhaps I have deciphered the question properly but I'm not sure.
Water that looks clear and colorless but has iron content is turned a brownish color when Cl2 is added because the Cl2 oxidizes the iron (mostly there as ferrous or other compounds) to ferric and that is brownish in color.

Answer 2

And I don't know "why" to remedy the water; I don't even know what you are asking.