Neons keep mysteriously dying :(

[A_nnnna]

Can anybody shed some light on why my tetras are suddenly dwindling in numbers?
I have a community tank set up made up from a siemese algae eater, a couple of mollies, japonica/cherry/green shrimp and one silver tip tetra (accidental purchase - as he was a lonesome chap in the pet shop and i took pitty on him) around 7/8 neon tetras and a recent addition (two weeks ago) of 10 black neon tetras.. everything was fine until two days in after having introduced the black neons, one or two died and i kind of expected it as a general stress of travelling sort of thing but then i noticed a few have tatty fins (but not with red streaks which would suggest fin rot) and their bodies a little battered looking (looks like scales are missing/ open wounds) but there's nothing in my tank to attack the fish nor is there a disease as all the other fish are fine. and i have just had to fish out a dead neon that doesn't show any sign or disease and his fins were all intact...
i'm now down to 3 black neon tetras, 3/4 neon tetra and the silver tip.
So i am confused to what it could be? i know the pet shop where i bought the black neons (and the normal neons several months prior) get their stock from a proper retailer (wholesaler?) of fish.
I've also had no issues with water parameters, i do a regular 10% water change (using aqua safe) and have kept fish for a good few years now.

can anyone help?

http://www.reptileforums.co.uk/forums/editpost.php?do=editpost&p=11931204

 

[anteatergoanna]

Hi, what size tank do you have? Introducing 10 fish at a time is risky if it's a small tank. How often do you feed them and what is your water change schedule. If you've had fish for years, you would know about the nitrogen cycle.
Sorry you are losing your fish.

 

[A_nnnna]

It's an 80litre tank... and it's not really populated by many fish..
i feed them every other day and do a partial water change once a week/every 10 days.
i do know about the nitrogen cycle, and surely if it's an ammonia/nitrate/nitrite spike then the other fish would be affected?

 

[Delapool]

It depends I've found. Neons are pretty hardy when established I've found but they are a small fish. Worth checking ph and temperature hasn't shifted (as well as the usual suspect of ammonia).

Apart from water conditions as mentioned above, next thought to check would be a bacterial infection of some kind.

Edit - I'd also increase pwc's for a bit. Always helps.

 

[Mama Karoti]

You should test for ammonia, nitrites, and nitrates. You should also be doing at least 25% water change per week if water params are ok, more often if they are not. Adding 10 fish at once to a tank that size probably sent it into a mini cycle.

 

[neonpedro]

Has anyone ever had a neon discolour? He looks perfectly healthy except he has no pigment around his middle on both sides? Any ideas?

 

[neonpedro]

Here he is

 

[anteatergoanna]

I've found if my fish is sick or stressed it loses colour. Odd how the middle is only affected.


Sent from anteatergoanna's burrow

 

[RadMax8]

Do they all exhibit the color loss before they die? It almost looks like neon tetra disease, based of the photograph. Unfortunately there is no cure for NTD.


Sent from my iPhone using Aquarium Advice

 

[neonpedro]

He's not dead and there has been no deaths for months. He's the only one showing these unusual markings. He's had them for a couple of months. Hopefully it's not NTD because these wee fellas have been through a lot since I got them!

 

[Delapool]

He's not dead and there has been no deaths for months. He's the only one showing these unusual markings. He's had them for a couple of months. Hopefully it's not NTD because these wee fellas have been through a lot since I got them!

How's his weight? Is his belly still looking good and not sunken?

 

[neonpedro]

Yes same as the others just with no colour. Still active still eating and grouping with the others

 

[Delapool]

Weird. Well apart from the belly concern he looks fine to me. It's odd to go a few months like that but schooling with the others is a good sign. Does he get chased or anything - runt of the pack?

 

[neonpedro]

No my neons are a friendly bunch they sometimes nip at the fighter at feeding time but never each other. There like band of brothers!

 

[Delapool]

Not sure if was asked but water conditions are ok? Nitrates low, etc?

Otherwise out of ideas on cause.

 

[neonpedro]

Eventually I got my tank cycled. It could be fall out from 'the dark times' of constant water changes and ammonia spikes. But were all good now on the readings front. So I guess it's nothing to worry about cos the wee dude is loving it in there!

 

[Delapool]

Yes, sounds good