For me all I ever used was the lil bottles of ichX but yours doesn't appear to be ich. Not quite sure what your guy has, haven't had anything like it myself. Hopefully someone else chimes in with their 2 cents on it and hopefully ya end up getting it diagnosed.
I would assume if your meds helped clear it up the first time that it would still do the job this time. It would just be a matter of prolonging the treatment period and then boosting the temp upto 80°f for a few days after the treatment is done. Atleast from the look of it ya atleast caught it early enough to treat still.