You should definitely have some amprolium on hand however the Apple Cider in the water may make a difference! We still aren't exactly sure what's going on.I'd imagined it was the fermentation doing the magic. I guess I'll do that for now until I can get the amprolium

It's probably not Coccidiosis at all, yes it takes a few days to die with Coccidiosis and usually they don't start showing symptoms until the end of the first week, usually not the middle. This could be from a host of things, you will probably never know. 