Lost 2 perfectly healthy looking fish overnight - Ideas?

[Fisherman Joe]

Woke up 2 see two Resplendent Anthias dead this morning, one was stuck to my MP40 powerhead and the other on the bottom of the sand struggling to breathe.

No signs of infection or damage from a fight. It was night time so all my wrasse were asleep in the sand.

I have a tank full of reef safe fish, Clowns and a yellow tang, Midas Blenny and such.

What could cause this? Temp looks ok, Alk and salinity all seem fine too.

 

[fishguy242]

hi, sorry to hear ,have you checked ammonia ? how long have you had anthias? eating well? all other fish ok?

 

[brandon429]

How did you prep the tank against fish disease, any quarantine and fallow approach or one of the other approaches