All my Tetra fish died overnight!

[Thatg1r1]

Hi all,
this is my first post so please forgive me If I've posted this in the wrong area.

2 days ago I purchased some Tetra fish to go into my cycled shrimp and Kuhli loach tank, all the new tetras seemed to be doing fine until today when I awoke to find all of the newly purchased tetras dead on the tank floor, some appeared to still be breathing so I've put them in a bucket for now, I don't have a spare tank. All my shrimp and Kuhli's are fine.

The dead tetras appear to be covered in what I can only describe as what looks like salt. Did I buy diseased fish or is my water bad and if so what do I do now? I've removed the dead fish and done a water change.

Tank details:
(Since it is bank holiday I can't go and buy a water testing kit just yet.)

Tank size: 50litres
Tank mates: 2 Bamboo Shrimp, 2 Cherry Shrimp & 3 Kuhli Loach
Plants: Lilaeopsis
Sand floor.
Tank temp: 74

 

[Hefin's Aquatics]

What's the ammonia, nitrite and nitrate levels like? How many of them did you have?

 

[NickAu]

The dead tetras appear to be covered in what I can only describe as what looks like salt.

Did it look like this

 

[DutchMuch]

your tank was overstocked. and understocked with certain fish. If It had ich you have bad water quality.

 

[Thatg1r1]

Did it look like this

Yes it looked very similar to that, but it's fins looked very frail

 

[Thatg1r1]

What's the ammonia, nitrite and nitrate levels like? How many of them did you have?

I'm unable to check the for those levels atm as I don't have a water testing kit, the shops are closed. I bought 12, perhaps too many at once?

 

[DutchMuch]

Like I said, bad water quality.

 

[snork6]

bought 12, perhaps too many at once?

I usually like to introduce my new fish one at a time. The most I would put at one time is 3. Putting 12 fish in at once might have disrupted your tanks bio load resulting in bad water, or one of the fish was already sick and infected the others but I doubt that could happen that fast.

 

[Essjay]

For the fish to have come down with whitespot that fast they could well have already been infected when they were bought.

You need to keep a close eye on the kuhli loaches for the next week or two. But because of the shrimps, don't be tempted to use a whitespot medication as a lot of them contain copper which kills shrimps and snails.
If the loaches do come down with it, whitespot can be treated with raising the temperature and adding salt - but i don't know if the shrimps would tolerate salt either.

 

[Munroco]

I agree with Essjay, they were most likely infected when you bought them.