Regular water changes will keep your aquarium a healthy place for your fish. http://www.petco.com
The importance of water changes. Aquariums are enclosed ecosystems that naturally attempt to stay in balance. Enclosed means that fish must swim, eat, and do their business in the amount of water limited by the size of the aquarium. It would be like you having to breathe, eat, and do your business living in a confined room with locked windows or doors. It would not be very pleasant after a while. Unfortunately, fish waste and any uneaten food can build up in the aquarium. As they start to break down, they also start to release ammonia, which is toxic to fish. Many times you cannot visually see this happening until it's too late. Simple water changes help by removing a portion of the aquariums water and replacing it with fresh water that is lower in ammonia and other dissolved organics. To keep them in check, you should routinely change about 25% of the aquariums water about once a month. It is never a good idea to completely drain an active aquarium. This greatly reduces the amount of beneficial microscopic bacteria that help keep your aquarium balanced. When performing a water change, it is also a good idea to clean the gravel. This can be done with a water siphon or water changer. These devices allow you to remove uneaten food, debris, and fish waste to keep your gravel looking nice, and helps keep your aquarium in balance. When you are refilling your aquarium with fresh water, always try to adjust the temperature of the water you are adding to closely match what is already in your aquarium. This will cause less stress on your fish and plants. Also, use a quality water conditioner that will neutralize chlorine and chloramines, making tap water safe for aquatic life.