Help! Dead fish every day.

[PheonixKingZ]

Help guys, please!

I have had dead fish for the past three days. On Wednesday, I had 1 Cory cat die, on Thursday, I had 2 die, and today I only see 2 alive and I just found the carcass of another.A

I now only have 3 neon tetras remaining, when I use to have 6.

What is causing all this? Please help.

All parameters are in check, tank is 29 gallons. Right now, there are 3 neon tetras, 8 Harlequin Rasbora’s, and 2 Cory cats.

Could the pleco be doing this? He has a super powerful tail, maybe while they were eating he thumped them?

I had to euthanize one last night because he was spinning in circles. (I assume swim bladder disease?)

 

[PheonixKingZ]

Also the corys tails are red, when I find their dead body’s. Could this mean anything?

@essjay?

 

[Naughts]

It's not the pleco.
Did you quarantine the new fish?

 

[Ch4rlie]

Agree that it’s doubtful the pleco will be the cause.

Will need more information, what are the symptoms, if any, other than the red tails you’ve seen on the cories?

Lethargy, gasping, erratic swimming, loss of appetite etc

 

[CassCats]

Did you have anything on your hands at all before handling their tank?

 

[eatyourpeas]

Did you add any plants? If they had pesticides it could account for the symptoms you are describing and not be obvious in parameters. Or as @NCaquatics points out, chemicals in your hands or aquarium cleaning items.

 

[Treestone]

The spinning in circles is a symptom of poisoning. Not many diseases can kill that fast in perfect water conditions, the ones that can are usually pretty obvious.

 

[Ch4rlie]

The spinning in circles is a symptom of poisoning. Not many diseases can kill that fast in perfect water conditions, the ones that can are usually pretty obvious.

Poisoning CAN be a symptom of fish spinning or swimming in circles but usually imho it’s down to neurological or bacterial parasites in the fish’s brain.

However, it’s very difficult to determine which it is without doing a post-mortem or similar.

So in either case, a large water change and perhaps treating with Metronidazole may be one option to try.

The large water change will dilute the poison, wherever it may have come from, there’s been a bit of a spate in hand sanitiser poisoning happening so it’s possible may be this but certainly can be from other sources.

Treating with Metronidazole may help in getting rid of parasites in fish brains or bodies so will not cause undue harm imho doing this.

But generally once fish start showing the symptom of spinning or swimming in circles, there’s little one can do to prevent the inevitable really.

But that does not mean you not not try, would still try treating the tank as it may work and at least it will treat the remaining tankmates.

 

[Colin_T]

I'm amazed I even have to ask for Pictures?

Have you added anything new in the last 2 weeks?

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It's unlikely to be anything on plants because all the old fish would be dying too, not just the Corydoras and neons.

Spinning in circles is normally caused by a bacterial or protozoan infection in the brain.

Red patches on the body or fins is bacterial.

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Before you treat the tank, do the following things.
To work out the volume of water in the tank:
measure length x width x height in cm.
divide by 1000.
= volume in litres.

If you have big rocks or driftwood in the tank, remove these so you get a more accurate water volume.

When you measure the height, measure from the top of the substrate to the top of the water level.

You can use a permanent marker to draw a line on the tank at the water level and put down how many litres are in the tank at that level.

There is a calculator/ converter in the "FishForum.net Calculator" under "Useful Links" at the bottom of this page that will let you convert litres to gallons if you need it.

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Remove carbon from the filter before treating or it will adsorb the medication and stop it working.

Wipe the inside of the glass down with a clean fish sponge.

Do a 75% water change and gravel clean the substrate. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn.

Increase surface turbulence/ aeration when using medications because they reduce the dissolved oxygen in the water.

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Add a broad spectrum fish medication that treats fungus, bacteria and protozoan infections. Use it at half strength due to the scaleless fish in the tank. Or you can try salt but if fish have been dying for a few days you will probably need more than salt.

If you use salt, add 2 heaped tablespoons per 20 litres (5 gallons). Keep salt in there for 2-4 weeks. You can use salt with most fish medications.

 

[itiwhetu]

What if anything have you treated this tank with

 

[PheonixKingZ]

It's not the pleco.
Did you quarantine the new fish?

No.

Agree that it’s doubtful the pleco will be the cause.

Will need more information, what are the symptoms, if any, other than the red tails you’ve seen on the cories?

Lethargy, gasping, erratic swimming, loss of appetite etc

No other symptoms, except the red tails when they are dead. I have not observed any living, with red tails. They look healthy on the outside.

Did you have anything on your hands at all before handling their tank?

No, I always wash my hands with super hot water and make sure not to touch anything.

Did you add any plants? If they had pesticides it could account for the symptoms you are describing and not be obvious in parameters. Or as @NCaquatics points out, chemicals in your hands or aquarium cleaning items.

No plants, just the usual trimming and replanting.

Treating with Metronidazole may help in getting rid of parasites in fish brains or bodies so will not cause undue harm imho doing this.

I do have some medicine... what medication is the Metronidazole you mentioned usually in? I have KanaPlex and MetroPlex.

Do a 75% water change and gravel clean the substrate. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn.

Increase surface turbulence/ aeration when using medications because they reduce the dissolved oxygen in the water.

I added an old filter from my 5g tank, but I cleaned it really good before. Could this be the issue?

I have this older water conditioner, but it’s not expired or anything. It does have aloe Vera, that’s why I got the Seachem Prime stuff. I was waiting for the old stuff to run out, before using the Prime. The issue is, I don’t have a single syringe that holds .01 mL of fluid, that’s crazy small.

What if anything have you treated this tank with

Nothing yet, just the weekly water changes and the substrate vacuums.

Here is a picture of the old water conditioner:

Expires in 01/2021

 

[PheonixKingZ]

There are three corys remaining now, here is a picture of two:

The red circle is the red tail on one of the dead ones, and the arrow is indicating the red tummy on the living one.

Here is the third one:

Tetras/Rasboras impossible to get clear photos, as usual.

——-

I take that back - I have 4 Neon Tetras and 8 HR’s. That means I have lost 3 corys and 2 tetras in the past 3 days.

 

[PheonixKingZ]

Water change/substrate vacuum will happen right now. Should I use the Vera stuff? Or try to use the Prime?

 

[Naughts]

Either water conditioner is fine as they aren't the problem. The problem looks like disease. It is probably from the new fish as they weren't quarantined but it's a slight possibility that the old filter held parasites. Did you lose fish in the tank that had the filter in? I would follow Charlie's advise and medicate to save the remaining fish and clear the tank of the problem. Cory 3 looks healthy right now and the raspboras seem good.

 

[mbsqw1d]

Sorry for your losses PK. On the upside, your snails and shrimp won't need feeding anytime soon ..