long-fin bannerfish just died?????

[2revup]

guys i got home tonight after work and i found one of my long-fin bannerfish dead. i have just done my testing it shows
ph:8.3
Ammonia:0
Nitrite:0
Nitrate:0.1 or less
temp is perfect

why did he die
i had 2 long-fin bannerfish now 1, 1 blue tang, and 3 blue - green chromies


tank is 76g

[dskidmore]

Any physical symptoms?
Any behavorial symptoms?
Is this fish new to the aquarium?
Anything else new in the aquarium or nearby enviroment?
What is your definition of perfect temp?
What is your salinity?
How long has this tank been running?

There are many causes for fish death when the water readings look ok. We need more infomation to make a diagnosis.

[2revup]

salinity 1.024
no symtoms or anything strange was just out of the blue.
there was no damage to his body after examination, has been in the tank only for 2 weeks, but was quite happy eating and active, and not picked on at all.
tank has been going for about 6 months
new live rock but that is it. and yes it has been cured before placing it in tank.
26deg was temp

[dskidmore]

At only 2 weeks in the tank, I would suspect he had some disease before you bought him. I take it you didn't QT him when you got him? Hopefully it doesn't spread to the others. Keep a close eye on everyone else in the tank for the next month or so.