I came home from class today to see that my Betta had HORRIBLY ripped fins. It just seems to have come out of nowhere. The water params check out normal, and I did a water change three days ago. There is nothing but plants and a rock formation in his tank, which I doubt to be the culprits as they are the same plants and rock formation that are found in my Delta tail/Cory tank, and my Delta tail's fins are perfect.
This happened two weeks ago as well, and I was finally excited for his fins to be growing back so nicely and quickly when this happened.
He is eating just fine and does not appear to be ill or unhappy at all. In fact, he is building a bubble next as I type this.
Does anyone have any ideas what is going on?