Hello; I allow my tap water to sit in containers for about a week before using it for water change. I have seen in other posts that 3 to 4 days is enough. This works for chlorine but apparently not for chloramine. I plug the openings of the containers with open cell type foam plugs left from vials of fruit fly cultures. This keeps the mosquitoes form hatching out in the house and allows movement of air thru. This also stabilizes the water temp to room temp. If you are fortunate enough to have good well water then no wait is needed except perhaps for temp.
i wait about a week if i was you to speed things up put a air stone in it keep the water moving pushing the chlor- to the top... remember it settles to the bottle.
I believe that chlorine can be taken out of the water by aging it but if you have chloramines in your drinking water you will have to use chemical. you can ask your local water source if there is chloramines present. They have reports on whats in the water all the time that you can look at to determine if resting is appropriate or the use of chemical is needed.
Great question and great input. I'm in a new house and just filled my tank up for the first time and definitely have a slight chlorine smell. If I decide not to age the water and use a product like Prime, can the water be added to the tank first during a water change and then add the Prime? Or do I have to use the Prime in a seperate tank, say a trash can, before I fill for a water change? No hijack intentions here as I am interested to hear what everyone's opinions are about the aging as well.