Clownfish and Tang Death

I recently bought a Yellow tang about a month ago. Out of no where my yellow tang stopped eating and was dead on the bottom of my tank. After a few moments I realized my clownfish was swimming alone, I than found my other clown on the bottom of the tank also passed. I'm not sure what could've done this. My foxface, damsels and 6 line are fine. My other clown is eating alright, moving around. The top of him looks like he was dunked in flower but it doesnt resemble Brooklynella (iv'e delt with that before). Any thoughts??

Params are great, Ammonia 0, nitrate < .25 Nitrite 0. Corals healthy, Anemone is healthy so i doubt its a chemistry issue.

Marine Velvet. Also after dealing wit Brooklynella I recently experience velvet in a QT on a CB Angel. Thanks goodness I learned and quarantined. Anyhow, when you say dunked in flour I rmembered that is what the angel looked like.

+1 it does sound like marine velvet

I dont have a q tank or one around to setup one. Will he eventually be able to fight it? He's still eating fine and i've been soaking the food in garlic. Also would it be Marine Velvet if it was only covering the top part of him?

It may only be on top for now. I first noticed it on my CB angel on back right over gill area but probably could show anywhere. It could possibly fight it off but unfortunetely (like the Brook we exerienced) it is hard to cure once it grabs hold. It kills rapidly but not as quick or suddenly as brook If it is velvet you probably see it get worse over the next day or two. Greenman, I am really hoping it is not velvet too much like the brook we both experienced. To give you some hope if it is velvet, had a purple firefish with the angel in QT at the time and never got it. After the angel passed, I kept that firefish in QT for another 8 weeks before had confidence to move to display. To date all is well. Wishing yo th best please keep us updated.

He's had this for about 2 weeks now. I think velvet kills much quicker if I'm not mistaken

Here is a picture

From best I can tell from picture it can resemble velvet but I agree if had 2 weeks it is a good chance it is not velvet. It does kill much quicker than that unless clown is a fighter. Now wondering if some kind of bacteria or fungus but that would not explain quick death of other fish. Hoping for the best I would double check parameters just in case false reading. Sorry that is all I got.