Help with Betta and Cory (survivors from my community tank collapse)

[Lauca]

These two have gone down hill today. The cory has been looking a bit lethargic for about 24 hours, the betta seems only to have gone down hill in the last 5. Both have been in the hospital tank for 4 days now.
The hopsital tank is being treated with a broad spectrum remedy as the cardinals in it have ich and bacterial infections.


In Hospital Tank
- 4 cardinals (with ich)
- 1 bristlenose plec
- 4 pepper corys
- 1 betta
They have all been exposed to ich, ammonia spikes and bacterial infection within the last week.



The tank parameters are:

pH - 7.56
Ammonia - between 0.00 - 0.25 (the tank has had a 75% water change daily for the past 4 days. I highly doubt the ammonia levels are high enough to cause a problem but I suppose it is a possibility)
Nitrite - 0.00
Nitrate - 5.0
Temperature - 24 celsius



I have had two days in the hospital tank with no deaths. I was hoping things were on the mend but today my female betta seems to be going down hill rapidly and my cory is not getting any better.
The Patients:

The cory lays near the top, often on its side. I will have a few swims round the tank a day but does not hang with its friends. It will swim if disturbed but is mostly lethargic. I have not seen it eat, but I cannot confirm either way.

The betta has been fine until today. She ate breakfast, and has been eating everyday prior to this. She was active this morning. I noticed around 5 hours ago that was becoming lethargic. Next thing I know she's laying on the bottom of the tank, breathing heavily.



I know there is likely no saving the betta now. She is dying and it's happened very quickly.

I have been careful not to overdose the hospital tank with the broad spectrum remedy. It's had daily 75% water changes and have been using the recommend amount of aquarium salt. I dont know what is affecting either of them so badly. The cory has been like this for a while, but it seemed to happen to the betta very rapidly. Any advice would be appreciated

 

[Lauca]

Betta has stopped breathing

I have given her a clove oil bath to make sure before I bury her.

 

[Colin_T]

The Corydoras could be stressed by not having anything on the bottom of the tank, no plants or hiding places, and no picture on the back of the tank. Quarantine tanks should has a thin layer of substrate, a backing, and somewhere for the fish to hide.

It could also be stressed out by the medication.

The Betta has a milky white film over the body and eyes and this is caused by something in the water irritating the fish. Again, possibly the medication if you overdosed.

 

[Lauca]

Thanks again Colin.
There are normally two potted java ferns in there but I took them out for the photos. No substrate (which I know isnt ideal) but has been making it easier for cleaning. Cory is doing fine today. I'm still not sure what happened to the betta. When I did the 75% water change, I didn't re-dose the water with the medicine (it was just filtered water) so not sure what she had a reaction too to cause her to go milky. My other two bettas who got the same new water but are in a different tank didnt have this reaction.

 

[Colin_T]

It was possibly a combination of stress from the illness, medication and being moved. It just got too much for the fish.