My goldfish started getting white spots on his tail about a month ago but I didn't do anything because they usually go away on their own. This time they are spreading. No behavioral changes or anything, thankfully, but the spots on her tail aren't getting any better. They're about 1mm in diameter, white and form in a line on the edge of the tail. Today one of the lumps appeared in the middle of the tail. It's definitely not ich because this fish had ich before and it looked totally different. I'm pretty sure it's not fungus either, since the spots aren't fuzzy but smooth looking. I'm rather attached to this fish as I've had it for about 7 years now. What do you think it could be?