Corydora immediate death

[juju67]

Hi guys,

I recently cycled my 55 gallon aquarium and got 12 bronze corydoras today. All the parameters are good, the tank is heavily planted, and the temperature is 24 degrees . I have two filters running a canister and an internal filter. Within 3 hours of corys been in my aquarium one was swimming sideways and resting sideways it shortly died however all other 11 were behaving normal and eating. I double checked and my water was fine so why did it die? It was healthy at the store. I am just curious could it be like a genetics thing or parameter shock? I floated the bag then dripped acclimated. do you think i was just unlucky?

 

[dudley]

Can you post your water parameter results since this is a newly cycled tank?

How long were the cory's in the bag from the store to when you released them in the tank?

 

[juju67]

Ammonia 0ppm
nitrite 0ppm
nitrate 10 -25 (hard to tell) ppm

it was around an hr drive so I'd say they were ni bag like up to 2 hrs? I don't have current photos because the lights turn on at night (I live in Australia) and its currently morning. I don't want to fiddle with the timing.

This was photo before i added the fish. I also did add thick vals on the left (5) and I added a heater a week before adding fish.

 

[juju67]

I'll send the new tank once the light turns back on tn!

 

[dudley]

Thanks for the additional info.

It's possible that the cory that died just was weaker or just didn't acclimate well. How are the other ones doing?

 

[juju67]

Thank you for help.

Last night I saw 9 corydoras come out to eat.

But when I fed I could only see 7 corydoras foraging around. But I've found 2 additional dead (Down to a possible 9?). I did a 25% water change just in case but the ammonia is till 0ppm Nitrite 0ppm and nitrate at 10ppm. All the dead corydoras seemed really fresh.

And the other corydoras seem to be doing fine foraging. Is this Ich?

In the past I've kept peppered corydoras in the past and had them breed. I'm using the same setup but higher temperature at 24 degrees. I had to reseal this tank so I took it apart and used aquarium silicone to reseal it. Used same substrate (a mixture of flourite red and sand though within the 2 days of the corydoras been here they've made the sand sink underneath the flourite red), rocks driftwood and canister filter, just added a internal filter. Im hoping this was jsut a bad batch and that I'm not doing anything wrong. Hopefully by the end of the week they stabilise. w

Also on a side note, I wanna sotck 30-40 ember tetras, 16 corydoras, and possible 1 bolivan ram? Is this overstocked? My canister filter runs 1000L per hour and internal does 600L per hour, which I may need to get a spray bar for as the flow is fairly strong. Could this be another reason to the sudden deaths?

Thanks for the additional info.

It's possible that the cory that died just was weaker or just didn't acclimate well. How are the other ones doing?

Thank you for the reply.

 

[dudley]

I'm sorry about the additional deaths. I'm not positive if the fish in the 1st pic has Ich or if that is just some debris on the fish from foraging.

I can't help with stocking questions so hopefully someone with more experience offers some advice.