I have had my betta named blondie for just over a year. He stopped eating....well he'd try to eat and couldn't get the food in his mouth...he got greyish and would lay at the bottom of the tank. now he has more color yet it looks like he might have reddening of his body and white patches however its hard to tell because of his coloring. he doesnt expel his fins out and flare like he used to. He has a hard time breathing and can't close his gills. I have him in a 3 gallon tank with a heater. his water is clear and he is the only fish in there. I got him pimafix and once I gave it to him he started darting into things like he was earlier and his body seems to have a curve to it like an s form. This morning I saw the white stringy stuff hanging from him in one place, but when I got home that was gone. I have no idea what to do. Any advice is greatly appreciated..also every time i do a full water change which is once every few weeks (he'd get too stressed when I did it weekly) I add a little aquarium salt too with the dechlorinator.