The two most common diseases that can wipe out a full tank that quickly, velvet and brooklynella. Both have a 6-week fallow period, though if you want to take care of ich while you are at it... 76 days.
I highly suggest adopting a QT protocol moving forward. It can be observation only, but it helps keep the really bad stuff out. Snails and inverts should be QT’d 76 days in a fish-less- QT. And for corals, at the very least dip and remove frag plugs/ excess exposed skeleton, etc; or QT 76 days as well.
I’m very sorry for your losses... I’ve been there [emoji20]
I highly suggest adopting a QT protocol moving forward. It can be observation only, but it helps keep the really bad stuff out. Snails and inverts should be QT’d 76 days in a fish-less- QT. And for corals, at the very least dip and remove frag plugs/ excess exposed skeleton, etc; or QT 76 days as well.
I’m very sorry for your losses... I’ve been there [emoji20]