Serpae tetras literally dying one by one

[Catfish Lover]

Started with 23 of them along with 12 peppered cories last September in my 55. Tank was instantly cycle with old media and lots of plants. A couple of the serpaes died within the first couple months, one was because it was deformed and the other was bullied because it was smaller. Everything has been fine since then until the last few weeks. I've lost 9 or so. No signs of bullying nipped fins but the ones that are dying are fine one day then the next swimming with nose up in air in same spot. No ammonia in the tank , no fish added, all peppered cories are still alive and well. Nothing has changed in the tank at all. This is obviously some tetra disease that's in the tank. Can anyone help?

 

[ArtistGardener]

Can you get a photo of them? Are there any visible signs when they start to act sick?

 

[Coyne]

It's also possible that some foreign substance found its way into the tank. Glass cleaner, hairspray, perfume... Stuff like that. It might not be a bad idea to run some fresh carbon in your filter for a little bit.

 

[Catfish Lover]

Not possible, anyways wouldn't the cories die also. Haven't lost one cory

 

[Catfish Lover]

Can you get a photo of them? Are there any visible signs when they start to act sick?

They Start swimming like they're reaching for something at the top of water, then they are dead within a couple days.

 

[Camescu]

Oxygen deficit? The Corys have a lower respiration rate...

 

[Catfish Lover]

Oxygen deficit? The Corys have a lower respiration rate...

How is that possible? I've got 2 fluval C4's running. Nothing has changed, been added to the tank. This is weird. One is literally sick right after one dies. Fine until then.

 

[Camescu]

I had a bacterial bloom and it started competing with the fish and the plants (overnight) for oxygen. The lemon tetras were the first to go. Gourami and most rainbows were rescued. The Corys chilled out and survived without rescuing.

 

[Camescu]

If it isn't an oxygen issue could it be tetra specific disease?

 

[Catfish Lover]

If it isn't an oxygen issue could it be tetra specific disease?

That's what I'm thinking, just wondering if someone has experienced this .

 

[Coyne]

Just so that Im understanding..
Its completely impossible that a common household product accidentally got into the aquarium and poisoned some, but not all, of your fish.
However, you feel that its very possible that a pathogen of some sort that only affects tetras made its way in.

Well, its your tank... so lets pull at that thread.
First you'll need to figure out what the pathogen is. I did a brief internet search on "Tetra Disease" and came up with something called "Neon Tetra Disease". I learned that despite its name, it does in fact affect fish other than Neon Tetras. Additionally, there are physical symptoms such as bloating, white patches and trouble swimming. You didnt mention any of these, so that's a bit of a question mark.

You'll also want to find out how it wouldve gotten into your water column so that you can take steps to prevent it from happening again. Since viruses, bacteria and parasites dont appear out of thin air, something you introduced into the tank mustve been carrying it. Most pathogens require a living host. Have you recently added any fish? Specifically tetras since we're looking for a disease that only affects tetras. Perhaps some plants or decorations that were taken directly from another aquarium that had tetras and then added to yours?

 

[ArtistGardener]

I feel the same. If there isn't a possibility of a contaminant (and unlikely since corys are OK), it has to be either a disease brought in on something new or oxygen deficiency.

When did you do your last water change? Have you tried a massive water change since you lost the first ones?

 

[Catfish Lover]

I do 50-60% water changes weekly. No fish, plants, decorations have been added in months. Only some of my floating hornwort was removed, because of overgrowth. I'm befuddled.