What happened to my swords? *sob*

[Kinetix]

I started with:
7 Cardinal Tetras
3 Schwartz' Corys
4 Blood Velvet Swords
1 Albino Ruby Shark

I'm now down to 1 Sword, overnight. Three died in the last 48 hours, and I don't know why. Conditions can't be that far from alright, as apparently they spawned in the last little while. I've found one tiny little guy (about 6mm in length) while picking out the dead fish. I haven't included him in the count. The male sword that is left doesn't seem to be doing too hot; he's active and eating but he's gulping constantly- not going to the surface for air, though.

My aquarium log is attached. Nitrobacter cycle completed long before this log starts, so no, it's not that.

November 11th measurements were taken shortly after picking out the dead fish. I have made a few changes to the tank in the last couple of days, most notably, adding a plant fertilizer called Nutrafin Plant Grow Iron Enriched .15-0-0. I also added a CO2 setup, but because the cap was leaky, no actual carbon dioxide made it anywhere near the water until I sealed it about 10 minutes ago. I suspect the fertilizer may be the cause, but this is extremely odd given that it's designed for aquariums and none of the other fish seem affected. There has been a noticeable increase in nitrates to 10PPM, however, that should be within permissable range, and I think it's elevated due to the dead fish anyway.

Ideas?

 

[BrianNY]

I know how frustrating this can be Kinetix. I don't think we'll have a definitive answer on why the swords died. They may have been ill when you purchased them and the stress of a new environment hastened their demise.

I've looked at your tank log and your tank has not yet cycled. The ammonia should be zero. I also think that you're doing too much fiddling with additives. It's true that products sold for aquarium use "should" be safe, but they aren't. I once killed several tetras by adding CO2 fizz tabs.

All fish will not react the same to sudden changes in their environment. Adding chemicals whether ferts, meds, or pH altering can be deadly. My uneducated guess is the pH down killed your swords. Fish that have a higher pH preference such as swords, do not typically do well when the pH is suddenly shifted downwards.

 

[Kinetix]

The tank is cycled. The ammonia reads 0.5 because of peat staining. The ammonia is actually zero. Because I have a visual impairment, I use a colour calibrator pen in order to read my kit. The slightly peat stained water lines up at the .5 kit reading.

You will also notice, BrianNY, the the pH has remained consistant at 6.5 and has not shifted from that point, and there has been no sudden shift. The swords lived happily with it for several weeks before dying suddenly within a short period.

Thank you for your reply.

 

[Zagz]

So sorry for your loss!

A cycled tank should always have nitrates of at least 10 ppm. Has the tank been set up as long as you have had the log?

I agree that the answer to the swordtail's death may not be easy. Sometimes these things happen and we don't find out why. If your other fish are healthy then it is a blessing only the swordtails were afflicted.

 

[TankGirl]

Based on your log readings I am leaning towards a "bad batch" of swords, for lack of a more obvious cause. It could be that they all had an internal parasite or a mild bacterial infection that was exacerbated by the move from the LFS to your tank, and over the past couple of weeks it did them in. Sometimes it is impossible to pinpoint the cause, unfortunately. It could be the water at the LFS or where they were bred was more alkaline than yours, and adjusting to the lower pH was a stressor, but that's hard to say.

I would remove the remaining sword to a hospital tank to prevent whatever this is from spreading to the rest of the tank, if possible, and perhaps treat him with salt, or a broad-spectrum antibiotic. Quarrantine new fish for at least two weeks in the future, and hopefully any problems like this can be prevented.

I'll move this over to the Unhealthy Fish forum.

 

[Kinetix]

I just got back from rememberance day ceremonies. He's not doing hot at all- he's gasping at the surface. All of the other fish are fine.

This is quite unusual that it happened so suddenly- and they did spawn successfully! They were incredibly healthy for two and a half weeks and then *boom* kaput. I'll have to assume it's the fertilizer additive; I won't use it any more. Now that I have plants and carbon dioxide, I won't be using the pH 6.5 buffer, either. My tap water pH has been around 7.2 recently, which is better than the 8.5 it used to hover at.

 

[Kinetix]

Changed another 5G of water today and added a carbon packet today. I'm not convinced it's a bad sword batch. They wouldn't all go within such a short period of each other....


...would they?

 

[TankGirl]

If they were all suffering from the same problem, they would. Especially since your other fish are not affected.

I use fertilizer in many of my tanks and I have not heard about them killing fish - I think the worst thing they can do is cause an algae bloom. However, often the fishkeeper's instincts about such matters are correct, since you know your fish's behavior before and after you perform certain maintenance activities on the tank. We often have a hunch about what we did wrong, and very often our hunch is correct.

 

[Kinetix]

On the upside- at least two fry have survived. They sure are good at hiding!

The sick guy-he's still in good enough health to run away real quick from the net, I can tell you that much.

 

[Zagz]

Then there is still hope. Good luck and keep us posted!