I'm sure that this is a common question.
I noticed that my male betta is now kind of clamping his fins a little and and the edged of all of his big fins look kind of tattered and shredded. He's lot listless and he still has a lot of energy.
I can't imagine what he's shredding them on. There's nothing sharp in there. Is he scraping himself on gravel or something? His tank water seems fine if a little cold because the heater is crap (and the wife won't let me buy new heaters because we already spent a lot of cash on these tanks).
Is this something to be worried about? It doesn't look like anything fungal or anything.