Instructions
Add tap water to your fish tank. If you are setting up a new tank, you should do this before adding fish. If you are changing water in an old tank, you should either remove your fish from the tank prior to adding new water or put the new water in a separate tank. If you put the new water in a separate tank, you must dechlorinate it there before adding it to your usual fish tank.
Follow the label instructions for using the dechlorinator. If there are no instructions, add one drop for every gallon of water in the aquarium. Avoid adding excess dechlorinator.
Wait 12 to 24 hours before putting fish in the water. Most dechlorinators take several hours to become fully effective. Your dechlorinator will have instructions giving a waiting time.
How to Dechlorinate My Water Using a Dechlorinater for Fish
Most tap water contains small amounts of chlorine that help to prevent the spread of disease and infection. Though these quantities of chlorine are likely harmless for people, they can prove deadly for fish because of their substantially smaller body size and because fish living in chlorinated water spend their entire lives swimming in a toxic chemical. Even trace amounts of chlorine can burn your fishes' gills, resulting in long-term illness and death. It's vital to remove chlorine from water prior to placing your fish in your aquarium, and the process for doing so is very simple.