Just lost my first discus, need to know why.

[fishbubbles]

So, 3 days ago I left home for a 2 day out of state trip and left my fish in the care of my girlfriend. She did daily water changes on all my fry and breeding tanks just like I always do. I instructed her to only feed the fish in the 265 gallon display tank once per day since she would not be able to do water changes by herself on that big of a tank.

I did a large water change on all my tanks and cleaned all the filters, wiped down the glass, and siphoned all the uneaten food which I do everyday anyways right before I left. All my tanks have readings of 0 ammonia, 0 nitrite, and less than 5 nitrates. Before I left, I had noticed a small pimple right above my giant floras eye. Some of my fish had pimples in the past but they had always cleared up by themselves in less than 36 hours. I had always thought that pimples were caused by bacteria in dirty water but I always pride myself in my water quality and could never figure out the cause of these spontaneous pimples.

Around 24 hours after I had left, my girlfriend called to tell me something was wrong. The giant flora had stress bars and it's eye was starting to swell. This came as a huge shock to me since I've yet to lose a fish and haven't had any real health issues in the past. I know it's hard to tell in the pics but this fish was over 7 inches and thicker than a 20 ounce ribeye.

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As you can see, this fish started to rapidly deteriorate, I immediately instructed my girlfriend to place the fish in my 40 gallon hospital tank along with 4 tablespoons of salt knowing that I was fighting a bacteria infection.

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She had to leave for work and found the fish dead 4 hours after being placed in the hospital tank. Does anyone have any ideal on what may have happened and how to prevent this from happening again? I have around 22 other adult discus in that same tank and everything has been fine since the incident.

[Filip]

I've seen and had pop eye disease in the past , but I've never seen that it might progresses so quick in just a matter of few days . This is very unusual IME.
He already have first stage pop eye on your first pic though. Maybe hes been like this for a while before it went south.

I hope someone with more experience on this will shed some light here .
Popeye and other eye related infections are ussualuly bacterial infections and antibiotics like furan are used to treat them .

[Second Hand Pat]

Hi Kevin, I agree with Filip that most likely this was an internal bacteria infection. I had something like this develop very fast and lost the fish over a couple days. Another possibility is the fish got spooked and slammed the glass really hard. Weird things like this seem to happen when you go on vacation. Sorry for your loss.
Pat

[NJDiscusGuy]

Wow- looks like a serious case of pop-eye.

[fishbubbles]

That's part of what has me so concerned, The fish died so quickly after noticing the very first sign that I'm hoping this isn't going to wipe me out. I spend about 3 hours per day tending to all my tanks and can tell you every fish's personality traits, patterns, etc. I'm always looking at my fish and in 24 hours this fish was perfectly fine to dead in an instant.