Blown a fin?

[jillnjasper]

I came into my room tonight to find my fish Jasper is missing some of his tail! The edge looks all raggedy, with the thin parts of his tail seemingly torn off and the thicker lines of his tail still, for the most part, in tact. I really don't think he's ripped it on anything...I have a plastic cup in my tank with no rough edges, a silk plant, and a filter, which Jasper has a liking to swim behind, but I see no rough edges...the filter is shaped like a cylinder. I have heard of bettas "blowing a fin," but I'm not entirely sure what that means, and if that's what's happened to Jasper. I know that fin rot is at stake, and will be taking measures to make sure he does not get it.

Also, if someone could tell me how to post pictures if at all possible? So I can give a visual? :)

[beetlebz]

how new is he, and how new is your tank? my male gets it alot, which I understand is poor water quality (i.e. if it was a new tank, mine is because of my snail lol) I would do small 5-10% water changes once a day for a couple weeks. that should help wonders!

[nav2008]

it could be fin rot. how long have you had him, what size tank, and how often does he get water changes? Or he could be turning into a tail biter... some betta have been known to bite off parts of their own tail.

[jillnjasper]

I've had him for exactly a month now. The tank is a one-gallon tank (I'm hoping to get a bigger tank soon, like a 3-gallon tank). I do have a filter, which I put in the tank about 2 weeks ago, but the bottom of the filter is so close to the bottom of the tank (because the tank isn't but about a foot tall, and I can't fill it all the way to the top so Jasper can breathe) I don't know how much good it does, if any at all.