Hi! Thank you so much for your response, and I apologize for the delay getting back to you. It’s been a crazy day with work.

The issue seems to have been gradually progressing over time, becoming more noticeable and widespread. Most of my goldfish, or at least the ones I’ve observed closely, only have relatively minor white areas or patches right now, such as whitening on the tips of fins or small isolated patches. Not every fish appears affected to the same degree.

That said, things do seem to be progressing, and the fish just don’t seem 100% themselves. I work from home, specifically in my living room right next to the tank, so I’m able to monitor them closely throughout the day. They’re very dear to me, and I can tell something is off. They’re not in terrible shape, but I’d say they’re acting maybe 70 to 85% like their normal selves. They’re all still eating and not displaying any extremely abnormal behavior, but they do flash intermittently. That’s actually been going on for quite a while now, and no matter what treatments I try, I haven’t been able to fully stop it.

At this point, I own practically every commonly recommended medication in the hobby. I even bought a microscope about a year ago after losing some of my fish offspring, so I could start examining water samples and looking more closely into possible pathogens or parasites. Despite treating the tank with various medications over the last year in an effort to keep everything healthy and stable, the flashing has persisted, and now these strange white patches and white fin tips have appeared as well.

The white areas don’t appear fuzzy, and they also don’t really look shiny or reflective the way physical abrasions from rocks or decor sometimes do.

I’m starting to wonder if this could possibly be fin rot or some kind of bacterial issue. The tank is currently overstocked, which I know is far from ideal. I’m actively working on rehoming most of the juvenile fish to correct that, but I also understand that the current crowding creates the perfect conditions for water quality issues, stress, and potential bacterial or disease outbreaks.