You need to know what's been going on to understand how frustrating this problem is. : ( To start at the beginning, about, oh, 4 months ago or so, my betta Seuss got a small rip in his tail fin (sorry, not sure of proper names.) I didn't put salt in his water or anything (stupid, I know, I didn't think it was a big deal,) and he ended up with fin rot. So I researched fin rot on here and started putting Aquarium salt in his tank and gave him a couple of salt baths. I also tried some Jungle Fungus meds, but no one on here really seemed to like meds over aquarium salt, so I stopped the meds and kept on with the salt.
After around 2 weeks, his fin rot started clearing up, so I did a 50% water change and didn't add more salt, so I could slowly wean him off of it, since it's not good to keep them on it. Well, the day after I did this, he had a new rip in his fins. (I had already removed the stupid plastic plant that did it the first time.) So back on the salt he went, and I swapped his new not sharp at all plastic plant for a not-sharp-anywhere, silk plant, and looked over his whole tank and found no sharp spots.
After a few more weeks of salt, I planned on weaning him off again, but that morning I found another rip in his fins! (all in different places each time, and they were more like holes in the center of the fin, not bites on the edges.)
So he's been on AQ salt for around 4 months now, because 4 or 5 times now he's done this. Finally, yesterday, I did a 50% weekly water change and didn't add more salt, because i'm sure it'll just give me more problems. : ( His latest rip was a small hole about two days ago in his (dorsal?) fin on his back, as I predicted, overnight it ripped all the way to the edge of his fin and split his fin in two. (will try to get pics soon.)
There is NOTHING left in his tank for him to get caught on! and I don't *think* he's biting his tail. He never has before and i've owned him for at least a year and a half now! Please! Any help, advice, ANYTHING you guys can give me would be so greatly appreciated! : (
-Veilfin, in a 2.5 gal tank, 50-75% weekly water changes, conditioned well water (nothing's changed there,) has a TOM internal mini filter and a tetra 2-15 heater. Water stays at 75-80* F. Gets mostly flakes, (only in the AM,) but I have started giving him Pellets about 2 weeks ago. 1-2 a day, a couple days a week for variety. no flakes on pellet days, and they are soaked in tank water first.
Oh, and the fin rot is completely gone.