What killed my betta? Looks white and fuzzy

*WARNING: Photo of dead betta below*

So my betta died and I found him like this! He’s all white, fuzzy, and fins look like they been torn apart. What caused this?

At first he couldn’t swim and I assumed it was swim bladder, then it clearly got worse.

 

What were your recent parameters? If you test them now, they will be wonky from your dead betta. Did you test beforehand and keep up with weekly water changes?

 

What were your recent parameters? If you test them now, they will be wonky from your dead betta. Did you test beforehand and keep up with weekly water changes?

I remember testing for ammonia which was 0. And yes, I did the water changes and conditioned the water properly. It was one day he suddenly couldn’t swim at all and then started hiding in plants then died. I thought maybe it was fungus since his body was fuzzy and white?

 

Looks like fin rot

 

I'm guessing he's not a crown tail betta. Looks like fin rot or an infection in general and that he's probably been going through that for some time maybe. If you have any tank mates, they could be responsible for some of the tearing of fins. Plastic plants are also known to tear betta fins. Otherwise big picture here it was probably an infection. If you get another betta and see something off with them, research, and then take action asap. As in water testing, water changes, possible aquarium salt and actual medications (general cure, erythromycin, etc.). Check your temperature often as too much change in temperature can lead to infections in fish due to stress and all that.

 

fin rot and blader failer from a parisite