How long does it take for dechlorinator to work?

Since it takes about 2-5 minutes for chlorine and chloramine to be neutralized, many companies officially state that you should dose the dechlorinator to the tap water in a separate container before adding the water to the aquarium. That being said, we always add the water conditioner directly to the aquarium and then pour in fresh tap water, and there have never been any problems.

For more information, read the full article on dechlorinators.