Sudden Death! No Other Apparent Symptoms

[pammy172]

Please help!! In the past two days I've lost two tetras - one rosy and just now a phantom. No symptoms - they literally just died.

The one yesterday was hanging around the top of the tank in the morning. Got home from work and it was dead. No obvious signs and it had been fine. Just now got home - all looked well then I saw a phantom just hanging in the water - thought it was dead, then it swam a little and I managed to get it in a sep little floating tank and it died. There's no visual symptoms at all.

Water tests last night - ammonia 0ppm nitrite 0ppm, nitrate 20ppm. Was going to do a water change tonight anyway. New tank finished cycling two weeks ago.

I'm convinced I'm missing a neon so am about to try and take the tank apart to find it.

Bought some new tetras of the phantom and neon variety at the weekend and one phantom is very fat - looks pregnant. They are all eating really well, no signs of stress. Swimming about and shoaling really nicely.

All new fish from the same supplier - Maidenhead at York

Tank is a 260l with two tetratec ex filters a 1200 and a 600. Lots of real plants. Stock:

9/10 neons
4 rosy tetra
5 phantom tetra
2 siamese flkying foc
6 leopard corys
3 rainbow fish

Added in three stages over the past 10 days. Corys and 5 neons from my prev tank and had to be rehoused urgently as a filter packed in.

Any ideas

 

[skimmy290]

it's probably was just a bad fish. unless other fish start to turn up dead, nothing to really worry about

 

[pammy172]

Found the missing neon - I now have ten again!! phew!! Just wish I knew why these had died.

 

[WILDER]

Any neons showing signs of a bleached out red stripe or a milky substance on the red stripe area.
The blue area on the neons does it look like a golden yellow colour.

If the neons red stripes are still vibrants and with losing quite a few fish I would add a bacterial med if no signs of flicking and rubbing.