lol.. theres always tang police out there somewhere!!
I'm gonna do some reading on mv and see if the signs and symptoms match at all.

Something else to keep in mind, a fish can have ich and marine velvet at the same time as well as any other parasite or disease for that matter. Unfortunately there is no written law that says a fish can only have one thing wrong with it at a time

Let's hope not.

Sorry for making a mistake with the number of tangs you have. I mistook 2" for 2.

The reason why I suspect lack of oxygen is that all the fish died quickly.
IME a pathogen like ich will take some time to kill all your fish.

Active fish like tangs are the first to go. You can see a tank which lacks sufficient oxygen
by observing the fish. They stay near the top and sometimes break the surface.

Don't know what causes it but the solution is to immediately place a powerhead near the top of the tank.

Leave the tank fallow for 6 weeks and start again adding fish slowly after you have observed them in a QT
Good Luck

This was the first thing I thought of as well and have experienced the rapid fish losses associated with it.

Cuz, you're not dosing any carbon sources are you (vodka, sugar, vinegar, Prodibio, Zeovit, etc)?

And Naesco please keep chastising people about improper tang husbandry - someone has to ensure more and more ignorance isn't perpetuated on this site.

no, not dosing anything.
so would the lack of oxygen be associated to the ich or say mv infecting the gills?
If done would adding the power head solve anything or just make things easier on the infected fish?

Ich will attack the gills creating difficulties for the fish in an already low oxygen tank

If a reefer sees fish dying it is always an excellent practice to place a large powerhead near to top of the tank to allow for more oxygen exchange.
Even if there is no lack of oxygen, more oxygen would assist a fish whose gills are damaged by ich.

o.k. I see..

So i'm left fishless but with all my corals still, how long should i leave things sit? 8-10 weeks? Anything in particular i should do or add during this period? stick to routine water changes, more? less than 15%? There is still a cb shrimp thats lovin life with no fish is he o.k. to remain in there?
Sorry for all the ???? but i definatelly don't want a repeat of any of this..

8 weeks should be long enough to leave it fishless. Take the opportunity to lower the nutrients by not feeding as much (do feed the shrimp once or twice a week though) and keeping up with water changes. It's also a good time to research the fish you would like to have in there and maybe set up a quarantine tank to quarantine all new fish... so you don't have the same troubles again

What Marie says.