More information you mentioned in chat..
Tank size: 10 (I believe this is meant to be a hospital tank.)
Maintenance: 50% water replaced every other day.
Water parameters: Unknown; Test strips used by petstore.
Temperature: 78 degrees Fahrenheit
Foods: Omega One
Treatment: 1 tablespoon per 5g of salt and Rid-Ich Kordon
Main problems: Ich, finrot
Comments:
Again, get the API test kit and test the water yourself because you cannot just trust your store to tell you the results are 'perfect'. Feeding is inadequate. The temperature must be lowered to 74-76. Your case is bacterial infection with extreme finrot in question. Bacterial infections tend to progress better in warm temperature.
Edit:
More information...
The goldies apparently have ich so this is a mixed infection. Treat fish for 14 days with salt only and no temperature increase at this rate. Do daily water changes and dose salt the amount of water replaced.
