Cory Cat Died For No Reason, Fish Are Inactive... What's The Probl

[TomShootsPhoto]

Hello my fellow aquarium owners...

So recently, just 10 minutes ago, I noticed that my cory catfish passed away... She was added to the tank about 3 weeks ago...
After I noticed her death, I lifted her out, and inspected: The only thing I could find that was a bit weird was her eyes. The eyes of the fishy where completely white...


I tested the water, and it showed to be normal.
Here are my results:

2 weeks ago I noticed that all my fish where inactive. The corys stopped eating and they started hanging out under a piece of driftwood,
And they only came out when I threw in some food- but after a min, they went back inside without eating anything...

What is wrong with my tank?

 

[techen]

Why is your ammonia test half empty?

 

[Chad]

Can you give us more details about the tank? Such as how old it is, temp, any plants, what other fish are in it, flow, do you have good surface aggitation...etc etc...maybe something will shed light on the mystery.
What kind of cory was it? Many like pH levels lower than what you have.

 

[TomShootsPhoto]

Why is your ammonia test half empty?

I accidentally spilled half of it out when shaking it...

Can you give us more details about the tank? Such as how old it is, temp, any plants, what other fish are in it, flow, do you have good surface aggitation...etc etc...maybe something will shed light on the mystery.
What kind of cory was it? Many like pH levels lower than what you have.

Yes, of course.

So;

Temp: 25 C, 77 F
Inhabitants: 1x Angelfish, 2x clownloaches (I know, they have to be in groups of 6), 1x bristlenose catfish, 4x cory catfish (it was 5 originally)
Size of tank: 300L/80 gallons
Plants: Java fern, Cabomba, poopie looking swordplants, possibly ugly rosaefolia, anubis
Surface aggitation: Hm... I do have my spraybar above water level, but there is a white film on top of the water....
Cory type: Corydoras aeneus
Heater: Comfor zone 300, working
Filter: All pond solutions 1000L/H filter, working
Lights: 1x purple powerglo, 30W 96 cm, 1x yellow glo 30W 96 cm

Everything seemed normal... But something is obviously wrong..

 

[Chad]

I know that some farm raised cory do okay with higher pH but I generally like to keep Bronze cory at 6-6.5 ish. I'm not sure the 7.4 would be THE issue but it is something to look into.

 

[techen]

I have bronze corys at around 7.4 and there fine, for now >.>

 

[TomShootsPhoto]

I'll lower the PH, but is that really the issue? There must be something else!
What about the white film on the top of the water? Why are my fish so inactive?

 

[Chad]

The film is why I asked about surface agitation. A film is common on water that isn't moving and if water isn't moving then oxygen can be low. I wouldn't expect the pH to be a problem so quickly but I still thought it was worth a mention. Since pH issues can cause stress and stress can eat up oxygen if there's not enough then it can be a real problem.

 

[the_lock_man]

I wouldn't start mucking about with the pH, that could cause more problems than it solves. As TC said, it probably isn't the issue.

I'm more worried about this white film - do you live in a hard water area?

 

[TomShootsPhoto]

Doesn't seem like it... According to this chart I actually live in a soft water place...
Last week, it was so bad that I could barely see trough the water on top. I lifted my spray bar from my filter above water level, took a bucket and tried to "skim down" the white film... Not so much luck, it's still there but not so visible. There are now a bunch of small particles in my water.

 

[Chad]

I wouldn't start mucking about with the pH, that could cause more problems than it solves. As TC said, it probably isn't the issue.

I'm more worried about this white film - do you live in a hard water area?

Right, I'm not saying change it right now or anything like that. I'm just saying it's an issue to look into. If you did decide to change it that would be something done over a period of time, carefully, and slowly.

 

[TomShootsPhoto]

Ok, thanks! But whats the problem? I read somewhere that when fish are inactive and dying I shouldn't feed for 3 days? Is this true or utter bullpoop?

 

[Chad]

That's not accurate. For some fish it could be much longer than that. For others shorter depending on the cause of death. Try doing something to agitate the surface of the water more and see if the fish liven up. That's a simple thing to do and will rule out low oxygen as the cause. The reason I keep mentioning this is because there are only so many things that cause issues and you've covered many of them with your tests. Oxygen problems is often one cause of "mystery" fish deaths especially where fish are bottom dwellers.

 

[TomShootsPhoto]

Thanks a bunch, I'll update tomorrow night!

 

[Chad]

Please do! I'm anxious to figure out what the reason is.