Fish dying/dead - Heavy Breathing - Need Help

[apex82]

As of now most are getting better. I did another water change of 20 gallons today and jammed about 3+ cups of carbon in mesh bags into the sump. The flame hawk and clownfish pair are almost back to normal. Moved the trigger and 1 chromis back into display after I saw flame and clowns eating. However, dragonette, trigger, 2 chromis and anthias still hiding and breathing heavy, but not nearly as bad as yesterday. I am hoping they might eat tomorrow. I am relieved no more deaths, hope it stays that way. So good news for the most part except for butterfly fish came down with major attack of ich...