Gilly (Galifinakis, because he is a lone wolf) lost a lot of fin shortly after I brought him home from the pet store. I had him in a filtered, heated 5 gallon tank. He also had what appeared to be ich (I noticed the sprinkling of white specks on him), which I treated. I haven't seen any indication of ich since then.
However, Gilly's fins just got worse. His coloring paled greatly, and he frequently had stress stripes. After waiting for a time after treating for the ich, I tried to treat Gilly's fins - I have tried Maracyn 2 and after that didn't seem to work, I gave him some "off" time and tried Betta Revive.
In an effort to try and control his environment a little more while I treat him, I bought Gilly a 1 gallon tank. To my surprise, some of his color came back and he has the stress stripes much less often once he was placed in the smaller tank. Unfortunately, I haven't seen much improvement regarding his fins. I tried treating with a combination of Maracyn and Maracyn 2, but it didn't seem to help.
This is Gilly when he had just come home (the plants were replaced by silk plants before very long - so I know constant catching isn't this issue):
This is Gilly after he paled and had stress stripes almost constantly:
This is Gilly in his new (hopefully temporary) home - his color is back, but his fins are at their shortest. They have been this way for at least a week. They have not decreased at all, but I haven't seen any regrowth, either.
Sorry my pictures aren't very high quality - I just had my phone to take the pictures with. I can't find my digital camera. Does anyone have any ideas/suggestions? I'm trying my best, and I feel like a fish-mamma failure.