pectoral fin torn?

[dmhendsb]

This morning I found a housefly in the tank. My betta is swimming crookedly and floating sideways. It looks like his pectoral fin may be knotted or torn. How can I help the poor thing?

[Oldfishlady]

Have some question....
How big is the tank, how much and how often are the water changes and when was the last one, additives used, filtration, live plants, water temp, how long have you had him and the set-up, have your tried any treatments or medications, is he still eating and does he look bloated or any other symptoms?