shredded fin

My beautiful blue veiltail seems to have a badly torn tail fin. This happened some time between 3 and 6 o'clock today, very sudden! In fact, I had noted today that his fin rot seemed to be completely healed, then only hours later, his tail fin is shredded. Nothing new had been added to his tank...

Hello, I'm a relatively new betta owner, I've had Thomas for a little over 3 weeks, initially in a .5 gallon cube from petco, now I've learned the error of my ways and have had him in a 2.5 gallon tank for the past 2 weeks. I am concerned that there has been some deterioration of his fins. One...

It recently came to my attention that I was mistreating my betta by keeping him in a vase. A couple of days ago I moved him to a 5 gallon aquarium that I dug out of the closet. The tank is a good 5-6 years old and I have no idea what brand it is or what kind of filter it is. The question I have...