Okay so I bought a betta fish over thanksgiving break of this year from my local pet store (bad I know) anyway he was doing awesome. I had him in a 6 gallon tank that was decked out. It had a filter, a heater and plently of entertainment. Over christmas I had to leave him alone for a week. (I could not get anyone to take care of him because I live in dorms) so he did not eat for a week. When I got back he was slow. The biggest thing was that his entire tail looked like it was shredded. Of course I felt so awful. I assumed that it was fin rot so I took him out of the tank and put him into a 1 gallon to make treatment easier. I started with a natural tea tree oil based solution. I did that for about 3 weeks and noticed no improvment. I then changed to a chemical treatment and again it has been about 3 weeks and no improvment. In fact it seems to be getting worse. He does not seem sick. He is always swimming around the tank and eats all the time. He acts the same as when I got him. I just want his tail to heal. Please any suggestions would help!