Fungus (?) on my Clownfish

[Snow_Phoenix]

Hi NR,

 

Need your expertise for a moment. Overnight, my Occy clownfish has developed a small white patch on one side of her body. The patch is woolly, so I'm assuming it's a fungus for some sort. I have several other fish with her in the tank which are actively feeding and swimming normally. The Occy is swimming normally too, but her dorsal fin is slightly clamped, so that doesn't look too good to me. 

 

How do I go about this? Is it possible to treat her within my reef, or must I isolate her and treat her separately? Must I treat all my fish, even though they're not showing any signs/symptoms, or will this stress them out more (take note I have an ornate leopard wrasse, who's quite sensitive to QT by nature, and also a small Hi-Fin, who might not make it in QT)? Also, what meds is the best to tackle this? I have Meth Blue, Malachite Green, Maracyn+ on standby. My LFS has limited stock of meds, but I can try getting the correct ones, if these are inadequate.

 

Please advise. Thank you.