All Dying, Slowly But Surely...

[chrismr]

Since the end of last week, my fish have been dying.

Lost 3 hatchets, 4 rummy nose tetras, 1 bronze cory, female agassizi, and a few pencilfish.

I just don't know what it is that is causing this. Have tested the water and all tests came back fine.

The tank has been running for about 6 months with no problems.

None of the fish have been looking particularly ill prior to death. They have all kept their colour and been active, up until I have found them floating.

What I am going to try tonight is to do a complete clean of everything in the tank. The fish will be housed temporarily in a large plastic tub, which will be kept heated, and I plan on rinsing and cleaning everything in the tank from plants to decor to substrate.

This may seem drastic, but it is the only thing I can think of which might help. I will then be medicating the tank with some anti-bacerial medication just in case it is not a pollutant, but a bacterial infection of some sort.

Problem 1: how do I clean all filter media without killing all the bateria?
Problem 2: Is this likely to kill the ramaining fish through stressing them out?
Problem 3: is this likely to even work?

 

[tttnjfttt]

You can't clean the filter media without cleaning the bacteria, but you can rinse it out in some dechlorinated water. If it is something other than a contaminant (something that got in the tank) this won't help, but it does sound like something may have gotten in there.

This will be stressful to the fish, netting them is always stressful, as is a dramatic water change, which it sounds like you are planning.

This is likely to work if it is a contaminant problem.

One more subtle symptom to look for is rapid breathing. This sounds wierd but I have noticed with my fish when they are breathing heavily, their mouths constantly open and close. Check for that one. Last week I almost said good bye to a betta that i thought was hopeless until I noticed the mouth thing, then the breathing.

 

[chrismr]

Thanks for the reply. But what is the rapid breating supposed to be a symptom of?

Not that there appears to be anything wrong with their breating though....

They have all looked perfectly healthy until they turned up dead. No wait, I take that back. The bronze cory had a fungal infection around one of its eyes. Put some Melafix in to try and sort this, but was dead the next morning.

One thing that gets me, is why have only some of each of the fish died and not all? Why only 4 out of 6 rummies, and 3 out of 5 hatchets? Surely if something nasty had gotten into the tank to kill these fish it would happen to all of them?

 

[dwarfgourami]

One thing that gets me, is why have only some of each of the fish died and not all? Why only 4 out of 6 rummies, and 3 out of 5 hatchets? Surely if something nasty had gotten into the tank to kill these fish it would happen to all of them?

Some people survived the Black Death. Some individuals are just going to be stronger than others. Not always the ones you'd expect, either.

Sorry to hear about your problems. I do hope things take a turn for the better soon!

 

[karlp]

I know they're not too many vets about with the know how for aquatic species, but if you have others look sickly or die, have you thought about taking it down to the vet to see if he can identify any specific pathogens, nematodes, signs of disease ?

I have done this before when there were steady losses of fish in the tank and the vet identified a nematode and prescribed medications that aren't available through the aquatic shops which cleared it up in the rest of the fish.

 

[tttnjfttt]

Rapid breating can be a sign of lots of problems, from parasites to bacterial, which is why i thought i'd check that one.

Fungus is usually a bacterial infection, do any of the other fish seem to have it? How is the tank doing today? If there are further deaths after your major cleaning, you may consider using antibiotics.

 

[chrismr]

Well, no deaths yesterday.

In response to your question tttn, no other fish had any fungal infections. It was only the one cory.

I started dosing the tank with Mixazin (I think that is name) last night.

This morning there were still no more deaths.

Hopefully when I get home, there will be no more floaters and the remaining fish will survive.

 

[tttnjfttt]

Good Luck!

 

[wheelyfeet]

Your tank is about the right age to, possibly, be suffering from "old tank syndrome."