I do not know what is wrong with him but his fins were always closed up and it looked like most of his scales were missing. But he is looking better than before but he is not up to full health yet.
Seachem's Paraguard worked for me (daily salt-water dips in Paraguard with aeration for 30 to 60 minutes). I successfully treated a mated pair of true perculas that were infected with Broolynella. They are now 8 months old and appear very healthy.