What Should I Do For Goldfish Fungus, Is There Something I Can Put Into The Tank?

Is it on just one fish or all? If it is on just one fish separate that fish into another tank and use the appropriate tank additive. After you have removed the sick fish do a 20% water change to his old tank to prevent his buddies from getting sick. If it is all of the fish do a 20% water change and use tank additive. www.goldfishinfo.com has info to help you be 100% certain of what is bothering the fish so that there is less of a chance of treating for the wrong thing. Going by that site you will then need a trip to a local pet store for meds or you can shop online. Here is another helpful site http://animal-world.com/encyclo/fresh/information/Diseases.htm