Option One (Recommended). Allow Chlorine to Evaporate Naturally, Find the tank you want to dechlorinate. Do not cover it. Place it outside or near a window. Over time, the chlorine in the water will dissipate from exposure to the sun and air. You will have about 10 Gallons of water in your tank which is important to note since how long you have it under the sunlight depends on how much chlorine is in the water. So when you put it under the sun, outside, or under the window, and leave your tank there overnight and the chlorine will 99.99% evaporate and you are ready to put the fish in your tank. It’s not recommended to do this with drinking water since contamination could still exist. Preferable place your tank away from air pollution for better results.
Option Two. Use an Activated Carbon filter. Activated carbon is a material that removes chlorine and cleans water. Choose an activated carbon filter that has been certified by NSF International, a nonprofit that tests and certifies water filtration products. Some activated carbon filters can be connected to your home’s water supply, or you can buy a filtered pitcher that uses an activated carbon filter.