Instructions
Change the water in the fish tank on a regular basis. You should siphon out at least 15 to 20 percent of the water in the fish tank every couple of weeks. Do not wait for the water to show signs that it needs cleaning; by then it may too late.
Remove any excess food from the tank after you feed the goldfish. If you leave the excess food in the tank, it can rot and eventually introduce some diseases into the tank that can infect your goldfish.
Establish a quarantine tank for any new goldfish or goldfish you suspect may have a disease. New goldfish introduced into the tank can pollute the water and infect the other fish. A quarantine tank is simply a small tank that you have ready to keep the new or infected fish.
Remove any fish from the tank that you suspect may have the early stages of a disease and place them in the quarantine tank. Some signs of disease are clamped fins, a goldfish who refuses to eat, visible spots or lesions, lethargic behavior or the fish remains close to the surface gasping.
Test the water in the tank for proper chemical levels. A simple test is to notice any changes in the color of the water in the tank. For more thorough testing, you need to purchase a testing kit at your local pet store. Here are some examples of the correct chemical levels for the tank. Ammonia levels should be 1 to 2 parts per million in freshwater tanks and below 1 for saltwater tanks. Proper nitrate levels are below 2 ppm.
How to Keep a Goldfish Disease Free
Goldfish are soothing colorful pets, but some owners make the mistake of thinking they require little maintenance. You can't take the drop, feed and forget attitude--this is a mistake. While it is true you do not have to take the goldfish for walks, bathe it or housebreak it, there are steps you must take to keep a goldfish disease free.