hey Kj, I did a quick search around on google, closest thing I could find that I could compare from verbal description, was marine velvet, however that is a parasitic infection, and you specifically mention cloudy eyes, which from my freshwater experience (sorry haven't had any sick slatwater fish yet) leads me to believe it is bacterial in nature.
I would say the first step, bar none, since you are allready losing fish, is to get it out of your display and into quarantine. If further diagnosis from more experienced members confirms bacteria, then I would say medicating it is in order... but I honestly can't tell... sorry... really wish I could help more.
Good luck.
"Maybe in order to understand mankind, we have to look at the word itself: "Mankind". Basically, it's made up of two separate words - "mank" and "ind". What do these words mean ? It's a mystery, and that's why so is mankind." ~ Jack Handey