So my Betta Biscotti is in a filtered 5 gallon tank, at 75 degrees. I just did a 50% water change today, adding conditioner. I normally do a weekly change of 20%. The water is 0 for ammonia.
His right fin seems torn nearly in half, and I'm not sure how he did it. I am a little concerned as it is slowing him down and he is resting more, but with the way he powers them to propel himself I am scared he may tear it more. His appetite seems decreased, which is a worry because he is a big eater, but he also jumped for food twice today, and after only one pellet this evening he stopped trying for food, which isn't like him. He is being treated with aquarium salt.
It doesn't seem life threatening, it just looks painful.