I bought them when they have been 2 months old. they were good shape and size. . Then I found them breathing very often. I treat them with metronidazole. Don’t help. I think it is getting worse. Plus my water is cloudy. 50 gl tank ph about7. middle hard water 6 discus $ moths old each. plus 1 SaE and 3 otos. water chages every other day 20-25%.
Breathing very rapidly is because of gill problem.
Metronidazole is to treat worms.
Do Potassium Permaganate bath then continue light dose for over night.
Repeat the treatment for 3 days.