Death!

[attibones]

I don't believe the OP is saying every time thy feed the fish die, but perhaps every time they feed OR the fish die, OP checks temp and other water stats.

 

[LeahMay]

Exactly as attibones said above! Sorry that was some poor writing on my behalf, they have had the same fish flakes as always!

 

[mtbdean]

Sounds stupid, but I had an established tank, had some Lemon Tetra's for years, one died one evening, every stat was perfect, and one by one they would die in the night!

 

[This Old Spouse]

What about getting a new container of flakes, just in case? Not that expensive, and would rule out at least one thing.

 

[eaglesaquarium]

Exactly as attibones said above! Sorry that was some poor writing on my behalf, they have had the same fish flakes as always!

 
Nah, my reading comprehension doesn't always match my IQ!!!  Ultimately, this is a mystery, and very strange.  Not sure where to go from here...  It might be specie specific. 

 

[TallTree01]

Is there a chance that it is in fact neon tetra disease but your neons are actually the NTD proof cardinals?
Maybe there was mold growing somewhere and the penguins are eating it?

 

[LeahMay]

Not sure how the flakes can be related to the deaths but i will open a new tub now (i stock up) to rule that factor out.
It certainly is a mystery and i was just worried all of them may just die. Ive been expecting my neons to die this year through old age but i certainly hadnt got this planned!
Mystery killer i guess!

 

[LeahMay]

Is there a chance that it is in fact neon tetra disease but your neons are actually the NTD proof cardinals?
Maybe there was mold growing somewhere and the penguins are eating it?

 
I think im good enough to spot the difference between a cardinal and a neon, but if i can get photobucket working i will upload a picture just to be sure!
Im getting a 6ft tank delivered sometime next week, did i oughta quarantine all the fish again before putting them in my new tank? (i know it needs cycling first) 
Not sure.  I have noticed, this morning, that one of the penguins has a small patch of discolouration towards his tail end. This is the first time ive seen anything different about them!
 
 

 

[eaglesaquarium]

Cardinals have the full red underbelly:

 
Neons only have about a half line of red:

 

[LeahMay]

Yes, didnt think i was that thick, been keeping fish for 3 years now hahaha.

 

[LeahMay]

How do you upload pictures? i have taken a snap of the patch i have observed on my penguin, it may be nothing but im guessing otherwise!
Its not brilliant quality, i only have a camera phone, but its in the thinner part towards his tail. 

 

[TwoTankAmin]

I think the focus should be on why its the penguins only dying. You say they went through Q but you do not indicate for how long. Some folks suggest one quarantine for months, especially if the fish might be of wild origin. I usually go for a minimum of 4-5 weeks with tank raised and 2 months or more for wilds.
 
Have you ruled out the possibility of internal parasites or worms? These can often take some time to reach the point of being fatal?
 
Neon tetra disease has visible symptoms both externally and behaviorally which Leah has not reported. So it seems sensible to rule that one out I think.
 
In the absence of having any better information, I would be inclined to move the penguins into an H tank that is bare bottom. This will let you observe the poop and keep an eye on the fish more easily. If you can get meds for worms you can treat and see what happens- most dewormers or not dangerous. If you have some fake plants you can add those to make the fish feel safer and less stressed. You don't need the tank cycled as long as you change water a lot. Add an airstone or small filter and a heater and it should be fine.
 
The one thing you do not want to see is for any of the other species to start dying. If it is something specific to the penguins or something that isn't, but has not yet spread to other fish, then moving the penguins to an H tank might help and can't hurt.
 
Lastly, I would rule out contamination. This usually kills multiple fish (even wiping out an entire tank at one time) in a very short period.
 
Short of taking scrapings, gill swabs etc,, it is hard to know if it is a specific pathogen either virus or bacteria in the absence of symptoms.

 

[LeahMay]

Oh i do apologise, I QT'd these guys for about 4 week, i brought them off a trusted local breeder so didnt see the need for an extensive QT. 
The only visible difference is the patch on ONE of the remaining penguins (picture on previous reply), I have moved them to a H tank a few days back doing daily water changes and being extra vigilant however nothing is coming of this. Their faeces and behaviour is completely normal to me.
Just noticed this patch develop over the past 2 days, this specific tetra is now singling himself off from the remaining group members and will stay alone towards one corner of the tank.
Worms? Can i just treat them for this without causing further harm if it isn't worms?

Thanks for your help.

 

[TwoTankAmin]

The fact you see a white patch means there are some symptoms. Unfortunately I am having trouble making it out from the pic. The water spots don't help. Any chance you can get a better picture? If you are seeing some sort of patches I would not start with dewormer.
 
Are you seeing any signs of the fish flashing/rubbing against things?
 
Normally dewormers and antiparasite meds are fairly benign and work reasonable fast. But it is more important to try and discover the nature of the problem in order to treat with the right meds rather than guess.
 
Here is one of the sites I use as a basic reference on common fish ailments. It is by no means the end-all be-all, but it is often a good starting point. I do not always agree with their specific medication suggestions though.
 
http/animal-world.com/encyclo/fresh/information/Diseases.htm

 

[LeahMay]

This white patch has only just developed, it wasn't present on any of the now dead fish or on any of the alive fish! Its hard to get a clear picture, i only have a camera phone and fish tend to swim hahaha.  

Nothing else has changed. No flashing, rubbing, gasping, or anything else. Just this one patch on this one fish!

yeah i was hoping to find the cause not just guess and watch them die in the process. 

Thanks