My Yellow Tang has HLLD/HLLE (hole-n-head) forming on head and appears to have Red Pest disease. Need recommendations on treatment. Other than a 10% water change a week ago, no other stressful actions occured in tank.

120g reef tank with: hippo tang (infested with ICH), red fire shrimp, 6line wrasse, 1 ocellaris clownfish, 4green chromis, 1 sally lightfoot crab, and several hermit crabs.

Water lvls tested good: PH-8.0, Ammonia-0, NO2-0, NO3-.05, Salinity-1.020