Ich is a definite possibility, especially if you were seeing the white spots. I’d also like to cover the possibility of secondary infection with those blotches.
You’ll need a bare-bones QT... no live rock or sand. Definitely no corals or inverts.
I would recommend treating like you would for marine velvet. You’ve already done a freshwater dip, so I wouldn’t do another and risk stressing her too much... but I would give her an antiseptic bath prior to transfer to QT.
Acriflavine is my bath of choice, as it also has anti-parasitic properties. Ruby reef rally and API Fungus cure are both good sources. Treat in a separate container (I use a 5-gallon bucket, with an air-bubbler and small heater)
After that, I would pre-dose the QT with kanaplex (antibiotic) and start ramping up copper. I’ve gone up to .2 Cupramine in the first day, and it’s been recommended to start at 1.0 with chelated copper if you decide to use Copper Power. Make sure the test kit you are using is compatible with your copper of choice, or get a Hanna checker.
Over the next few days slowly add copper until you get to .5 ionic (or 1.75-2.0 chelated).
I would also try to source metroplex and furan-2 to have on hand, just in case the kanaplex can not handle the infection, or new symptoms arise.
I think there is a *slight* chance could be early brook (btw regardless the clowns will need treated also since they shared a tank) but most likely it ich or velvet and a secondary bacterial infection.
I hope that helps, good luck!
