Dechlorinated Water for Aquarium

Chlorine or chloramine is added into public water for disinfection - to kill most bacteria and viruses. 

Chlorine and chloramine are harmful to all live creatures.
 I use dechlorinated New York tap water in all my aquariums with fish, plants, critters. 

I fill up a jar with cold tap water at least a day before using it in aquariums.

 It takes about 24 hours for chlorine to evaporate.
 Keep the tap water in an open jar for 24 hours to dechlorinate it. 

24 hours later the water is safe to use in aquariums. 

Some cities disinfect public tap water with chloramine. 
Chloramine does not evaporate from water! 
Most kitchen water filters remove chlorine and chloramine (among other bad things) from water, making it suitable for aquariums. 
Check it with your water filter maker.

 Bottled water of most popular brands is suitable for aquariums.

 Fresh water from creeks, ponds, lakes, and rivers is normally free of chlorine or chloramine. 
Though, this water may come with germs and critters. 

 Rain water is also suitable for aquariums ;) 

Those are sources of water I have tried or currently use in my aquariums. 
Have fun and happy aquariums :)