When you using salt treatment it should be right dosage or it will not help. If you using 3-4 tsp for 10 gall it not helping. The right dosage minimum 1tsp/gall up to 3 tsp/gall.. I am going to give you a few links so you have idea about salt dosages.
check #7 from Sakura she is one of the most knowledgeable on the forum.
Check #3 Tikibirds recommendation
And especially if he is still bloated and pineconning you really need to use right dosage and i would really do 3 tsp/gall pre dissolved with daily water changes + medications.