Hi Edith. I'm glad he's made improvements. :) I'd love to see pics of him so here's how you can upload pics.
Just below the message box where you type your reply, you should see a button that says "Go Advanced." Click on that. The screen will change. Above the message box, you should see a paperclip icon. It'll be next to the smilie face guy. Click on that. Click on "Choose File." Find your pic file and click on it, then click "Upload." Repeat as necessary until you've uploaded all your pics. When you are done, close the extra window and then click on "Post Reply." Voila! :)
For the moment, I don't think you need any more medicine but pics will help me see how bad (or good) the fin rot is right now.
Now that he's out of the salt, you can go back to a regular water change schedule. He should be okay with that. One 50% and one 100% change per week, unless you have a filter. If you have a filter, it's 25% and 50%.
Looking forward to seeing how he is. And you're welcome, I'm very glad I can help you out.