abscess

Hello, I made a post about this problem of a white spot on my betta's head on Jan 1st this year. Since then the spot has turned into a form of growth. I have read up on bettas of this species being more prone to getting tumours. However, the white growth on my betta has a different look to it...

Attached are 3 photos, the first is from the day I got him (August 1st, 2021) and the rest are from today. I had gone on a trip and left my family to care for my bettas for a couple days and have returned to this, which I think is an exploded abscess? I’m not sure how to care for his growth or...

Around 5 years ago I rescued these 3 goldfish. They were super tiny, and in that time I’ve upgraded them from a 2 gallon tank, to 10, 29, and now 60. I’m running a Fluval fx4 on the tank. I do weekly or large bi-weekly water changes. I always considered them to be thriving as they continue to...