Frequently Asked Questions
9. Do I need to treat the water before I use it for my fish?
Yes. Your drinking water contains disinfectants to inhibit bacterial growth. These disinfectants can kill fish. The water supplied by the DuPage Water Commission contains chlorine. Chlorine can be neutralized by adding the appropriate chemicals, which are available at most pet stores. Chlorine can also be removed with a granular activated carbon (GAC) water filter. Chlorine can also be removed from the water by letting a container of the water sit exposed to the atmosphere (uncovered) for at least 48 hours.

Some fish, particularly tropical fish and koi, are also sensitive to rapid changes in the temperature and pH of the water - even small changes. If you are going to change the water in an aquarium or pond, or add a significant amount of new water, consult an experienced fish care expert for tips on how to accomplish this without shocking or killing your fish.

Some people may be concerned that water harmful to fish might not be safe for them to drink. This concern is not necessary. Humans and fish use water in very different ways. When humans drink water, the chlorine is neutralized by our digestive system before it enters our bloodstream. When fish "breathe" water, any chlorine present enters their bloodstream directly. This interferes with the fish's ability to take oxygen from the water and can cause the fish to suffocate.