Losing Cardinals, One By One...please Help! :)

[ey2006]

In my 29g tank, I have (or had) 10 cardinals, 6 neons and 3 small bronze corys.

I've had the cardinals and neons for a month now, the tank has been up and running for about 15 weeks now.

Water stats (from the test I did yesterday):

Ammonia 0
Nitrite 0
Nitrate 10
PH 7.0

Could it be due to the fact I removed the airstone from the tank? In my bigger tank (240L) my corys spawned 500+ eggs and I've had to use an airstone for them so I used the airstone from the small tank. In saying that, in the smaller 29g tank where the cardinals are, I am using a Hang On Back Filter which already provides some aeration.

Would the removal of the airstone be the cause of deaths for the 2 cardinals that I have lost within 24 hours?

This morning, I noticed one of the cardinals lying upside down on the substrate, with all the blue stripe completely faded and half the red stripe also faded. I took it out immediately and another one died just then, with the same appearance.

The cardinals don't seem to be showing any signs of illness or disease so I have no idea what is going wrong.

I understand that cardinals should be introduced to a tank that has been up and running for at least 6
months, but I didn't know this when I got the cardinals, but I also read that if the cardinals survive the first week or two, they should be fine and healthy in the medium to long term.

I'll test water again right now and see if ammonia or nitrite has spiked and post back.

Any suggestions would be greatly appreciated.

 

[ey2006]

I just did a 40% water change and raised the temp from 24C to 26C.

I then tested the water again and these were the results:

Ammonia 0
Nitrite 0
Nitrate 60
PH 6.8

With PH dropping, this is more a good sign than bad since the cardinals prefer softer water....but I'm not sure what the deal is with Nitrate rising so much. The tap water's Nitrate reading is zero.

Is there anything I can do now?

 

[nmonks]

Sorry to say, sounds like the dreaded neon tetra disease (NTD).

As far as I can tell, all neons come with NTD as a free gift. I'm an aquarist with 20 years of experience and I've kept all sorts of stuff from seahorses to spiny eels, and neons are the one fish I don't feel lucky with.

NTD is untreatable.

The giveaway is when you have your neons or cardinals dying one a week.

It is passed on (most of the time) by one fish pecking at another, particular when a healthy tetra nibbles at the corpse of a recently dead tetra. So the best way to break the cycle is remove any fish that shows any sign of illness. Do this with extreme prejudice! Since it's going to die anyway, you may as well euthanise it straight away.

Sick fish tend to swim away from the school, lurk in corners or under plants, and basically look off-colour.

Cardinals are hardier than neons, so all else being equal, you should be able to stabilise things by removing any potentially infected fish. Optimise filtration and water conditions as far as possible, but don't make sudden changes in water chemistry. Adding an airstone and raising the temperature to 26 C sounds a find idea. Make sure you are feeding them a good diet, and certainly don't risk any live foods for a while.

Once you break the cycle, the fishes' immune system seems to knock back any residual NTD, and the fish stop dying off. Be ultra-careful about introducing any new fish though... certainly avoid rushing out and buying any more tetras for a while. A quarantine tank might make a lot of sense, if you have the room for one.

Cheers,

Neale

 

[ey2006]

Thanks very much for the reply Neale, its appreciated. I feel so helpless at the moment as I can't do much to prevent further casualties.

So does that mean cardinals can get NTD too? Its funny, because if it was NTD, I would have expected the neons to fall first. I had 10 cardinals and 6 neons, and now the count is down to 8 cardinals and 6 neons, if I don't stop this outbreak soon, i'll have more neons than cardinals!

I honestly thought my cardinals and tetras were sweet, since I've had them for a month now, if anything was to go wrong, it would have already happened.

Is there any other way to tell if a neon or cardinal has NTD apart from separating itself from the group or the other features you mentioned? The thing is, everytime I've checked on them today, they seem to always be swimming in a group and none of them look sick or colourless. Though I must note that when I just turned the tank lights off, I noticed all of them losing their colours, but could this be due to stress or them resting?

Hopefully, non all of them have NTD. Can NTD spread? Does the water stats play any part in NTD? I was actually thinkin about moving the cardinals to the bigger 240L tank, but that has only been up and running for 2 weeks so I don't think it will help much.

Should I continue feeding them? When I fed them today, some of the cardinals/neons ate while others didn't.

Cheers.

Sorry to say, sounds like the dreaded neon tetra disease (NTD).

As far as I can tell, all neons come with NTD as a free gift. I'm an aquarist with 20 years of experience and I've kept all sorts of stuff from seahorses to spiny eels, and neons are the one fish I don't feel lucky with.

NTD is untreatable.

The giveaway is when you have your neons or cardinals dying one a week.

It is passed on (most of the time) by one fish pecking at another, particular when a healthy tetra nibbles at the corpse of a recently dead tetra. So the best way to break the cycle is remove any fish that shows any sign of illness. Do this with extreme prejudice! Since it's going to die anyway, you may as well euthanise it straight away.

Sick fish tend to swim away from the school, lurk in corners or under plants, and basically look off-colour.

Cardinals are hardier than neons, so all else being equal, you should be able to stabilise things by removing any potentially infected fish. Optimise filtration and water conditions as far as possible, but don't make sudden changes in water chemistry. Adding an airstone and raising the temperature to 26 C sounds a find idea. Make sure you are feeding them a good diet, and certainly don't risk any live foods for a while.

Once you break the cycle, the fishes' immune system seems to knock back any residual NTD, and the fish stop dying off. Be ultra-careful about introducing any new fish though... certainly avoid rushing out and buying any more tetras for a while. A quarantine tank might make a lot of sense, if you have the room for one.

Cheers,

Neale

 

[Bloo]

Just something else to consider - I've never had success with neons or cardinals in hard water, alkaline water - and they just slowly die off (though not at your rate). Do you know what your gH & kH is ?

 

[nmonks]

Yes, cardinals can get NTD, and so can a few other small tetras. There's no reason neons should "catch it" first, it's simply a question of which fish picks up the parasite first.

Both neons and cardinals change their colours in the dark. So that's normal.

Assuming they're all schooling properly at the moment, you're fine. But as soon as one looks a bit peaky, then swoop on it! Don't prevaricate.

Yes, feed them normally. If anything, make sure you're feeding them well and each fish is eating, since they're immune system is basically you're only ally in that tank. Obviously monitor nitrites, and don't overfeed. I'd vary the diet if I could; if all you're giving them is flake, then they may get bored with it. Gamma-irradiated frozen foods are safe and most fish love them. Live brine shrimp are another safe option (because they're raised in salt, not fresh, water).

The evidence for NTD being transmitted by, say, water on your hands or on a net isn't convincing. Like dropsy, it doesn't seem to be contagious through the water, only by fish-to-fish contact, where internal fluids from the sick/dead fish get into a healthy fish. Even so, adopt sensible quarantine procedures if you have other fish tanks. Don't move fish between tanks, wash your hands, etc.

Don't be too disheartened. I had an outbreak of NTD about 3 months ago when I got 22 cardinals from 2 different shops. It seems (touch wood) to have stopped, and I have a fabulous-looking school of 17 cardinals. Provided you step in to intervene, it isn't a death sentence for every fish in the tank.

Cheers,

Neale

PS. Bloozoo's comment about water chemistry is a good one; I have yet to see anyone really succeed with cardinals in hard, alkaline water. Given your pH is less than 7, can we assume you have softish water?

 

[ey2006]

Thanks for the replies. Unfortunately I don't have test kits for GH and KH so I don't know how hard or soft the water is.

However, I have lost another 2 cardinals today and this time I saw them both shortly before they died. They were both swimming upside down and totally struggling to breathe, I took them out and ended their misery.

I've now lost 4 cardinals in 2 days, and surprisingly I've not lost a single Neon yet even though it seems like its NTD that I'm fighting with at the moment.

I did another 25% water change today and tested the water, the stats were:

Ammonia 0
Nitrite 0
Nitrate 40
PH 7.2

I fed the group of cardinals and neons today, some of them ate while the others weren't interested. I noticed they aren't as active and enthusiastic during feeding time as they normally are.

Should I move all the neons and cardinals to my bigger tank? It hasnt been up and running for long, but the water stats in that tank seem to be heaps better.

 

[nmonks]

No.

Several reasons. For one, you may transfer NTD to the other tank, and wind up with two aquaria within which you cannot keep neons and cardinals.

Second, moving the fish will stress them.

Third, since you can't measure things like hardness, you have no idea how similar the water chemistry is in the two tanks. Taking the fish from one set of conditions and dumping it in another is a good way to kill a fish.

For the time being, sit on your hands. The NTD will either go away by itself (as it seems to, eventually) or kill off all your neons and cardinals. But at some point you will have resolution. All you can do for the moment is make sure water quality is excellent, and offer the fish a variety of foods to keep up their strength (my cardinals enjoy mashed frozen prawn, and hard boiled egg yolk is sometimes popular, too). Small brine shimp are a safe live food.

Cheers,

Neale

Should I move all the neons and cardinals to my bigger tank? It hasnt been up and running for long, but the water stats in that tank seem to be heaps better.