Is this Fin Rot or Tail Biting?

[Colibri]

That could also contributing to the stress your fish is having. Try the siphon, if you don't get one with a "bomb" you can press it can be a little tricky at first, but once you "find the way" it's really simple. My bettas are very curious every time I siphon their tanks and get very close to see what's going on. !

[Connieconcon]

What do you mean by "bomb"?

[Colibri]

Hehe, I meant pump. Sorry!

[Connieconcon]

Oh ok! :D Thanks for the clarification!

[shinybetta]

Looks like tail biting. I don't see the usual black edges of fin rot. Try entertaining him. Does he like playing with marbles?

[Connieconcon]

I've never tried marbles! Maybe I should try that. I was thinking about getting him a new hiding place. All he has right now for hiding is the floating log.

[shinybetta]

They prefer colorful marbles. Mine circles it, then pecks it, then goes back to circling. My shrimp love marbles to

[1fish2fish]

I don't think that is tail biting. Tail biting looks like they took chunks out. You can usually see "C" shaped cut outs that are the size of their mouths.

Do you have plastic or silk plants? I can almost guarantee you that its your plastic plants that are the cause. IME it doesn't matter how soft the plastic is, eventually some part of it will snag the fish's fins.

[Connieconcon]

He only has silk plants though.

[Connieconcon]

When I got him he had a plastic plant, but I took the plastic out a month ago and his tail is still deteriorating.