Is it necessary to use a water conditioner if I were to age tap water. I know I have seen it mentioned somewhere on the forum before that over time the chlorine will disperse or something like that when the water is left in a bucket.
If one is certain that tapwater is treated with only chlorine, then leaving water to set for 24 hours would allow chlorine to dissipate.
However, here in U.S. much of drinking supply is treated with chloramine which is chlorine/ammonia.
For this water,, it would be wise in my view to use dechlorinator that addresses not only chlorine,but ammonia as well.
Some say that chloramine treated water could be safe after setting for a week, and other's who perform smaller water changes in larger tank's, or planted tanks, don't treat water at all and let plant's or biological filter deal with the ammonia from chloramines. But surely chlorine and or ammonia is easily addressed with use of conditioner such as PRIME so it is what I choose to use whenever I change water from tank's .