I don't know what it is but he just started being lethargic, not moving much. So I did a complete water change, put in the aqua safe, and the aquarium salt. He still didn't move much then all of a sudden he started freaking out, jumping out of the water, sinking to the bottom, floating on his side.
The tank is 2 gallons the temp is 78-79 degrees. I put in 1 tablespoon of salt. I honestly don't have a test strip to find out levels. Any ideas or questions would help, I moved him to a small hospital tank to see if he changes. Also he lets me touch him no problem with pretty much anything and wont swim away fast like he used to. He seems to be a little bit more active in the hospital.