My Betta has more of a split down center of causal fin. I think he caught it on the thermometer because I caught him going around it. I removed it. The fin also looks a bit tattered on some it’s edge. Tha tank is kept clean and is cycled. Parameters are all good, 0,0, and 10.Should I just keep him in clean warm water and watch? I have aquarium salt but heard that betta’s don’t tolerate it well. Help, please!