nothing to add regarding the 'disease' (I also thought cotton mouth too) but I just wanted to add please be careful using salt as a treatment with cories in the tank. Cories can not tolerate salt baths (adding salt to the aquarium) It would be safer to 'dip' the fish in a seperate container before adding the fish back to the tank. If you have a seperate tank to put the tetra's in though a salt bath can work there.