Hi, my betta has been with me for almost a year. He was doing fine until about 4 days ago when I noticed he was lethargic, is only swimming to the top, gets some air or eats 1 or 2 pellets of food, but it seems like he cannot stay afloat cause he goes up but sort of let go of himself immediately. Then, he reminds on the bottom of the tank on his left side. His color remains intact as well as his fins and he is eating.
I do not have a filter on his tank but it has been like that since day #1, about 1 year ago. I keep it clean and did clean it when noticed his behavior but nothing has changed.
Could he be dying or is he just sick?