Probably mixed with wild. Here are your choices. Each must choose their own way of fighting disease in the tank. It sounds like you want a clean environment and will be pretty vigilant. But, here they are:
1) Remove the fish and use a qt to house them for the next 76 days and keep the tank fallow (fishless) with no new additions of anything! Then, treat the fish with at least a metronidazole/prazzipro drug. Then, from now on, qt everything. Fish, coral, inverts, rock.
2) Let it ride. If the fish become ill then remove them and treat and go fallow. Same then as number one.
3) Let nature happen. If they die, wait to add more and just make sure every fish is healthy enough to fight disease when added.
Or some variation of any of those. Sometimes there is no right answer. We all run our systems different. These are just some of the choices I see. Although, I know what I would do and probably you too.
Good luck!