Cory death in new aquarium

[elamysmith]

Hi everyone!

Brand new fish keeper here from France. Nice to meet you all!

I have a 60l/15gallon planted tropical aquarium.

• Started cycling it for a week before planting it.
• Cycled it for 4 extra weeks until all parameters in the right ranges.
• Introduced 3 cory catfish (1 bronze, 1 albino, 1 spotted -they call it "pepper" in France). The shop said different colours would be fine together. Same day added 5 neon tetras. Everyone seemed fine. Bronze cory was super active and unafraid from the start. The other two hid a lot, which I believe is normal at first.
• 2 days later, we introduced 5 more tetras and a couple (male and female) dwarf gouramis. We're stopping there as I believe the biomass is maxed out.

48 hours later, I found the albino cory dead at the bottom of the tank. I've not noticed any aggression from the gouramis, or any issues between the fish. The tetras stick together, the gouramis explore alot but general stick together in the same areas, the corys ignore everyone and just hoover up the bottom of the tank.

Only think I noticed was the albino at the beginning would swim up a lot to the top area of the tank, and sometimes when he was on the bottom, he sort of suddenly turn on his right side, "spaz out" a bit (sorry for the term, but I can't think how to explain it), then swim off.

I rechecked water parameters and everything looks fine, everyone else looks healthy.

 

Any ideas what might have happened?

[Dacotua]

Did you do a large water change before you added all your fish? Whenever I do a fish-less cycle, I do a 80% water change before I add my fish.

Sometimes there can be things in the water you can't test for.

Sometimes fish just die when you add them to a new environment. Stress can kill a fish quicker than anything.

[Tlindsey]

On 4/1/2024 at 1:23 PM, elamysmith said:

Any ideas what might have happened?

It's various reasons the one I've experienced is that the fish was not healthy although it looked healthy. 

I suggest not to add anything else to the aquarium.  I would wait for about minimum a month and hopefully things remain good. I would quarantine any other fish prior to adding in the future. 

[elamysmith]

On 4/1/2024 at 8:39 PM, Dacotua said:

Did you do a large water change before you added all your fish? Whenever I do a fish-less cycle, I do a 80% water change before I add my fish.

Sometimes there can be things in the water you can't test for.

Sometimes fish just die when you add them to a new environment. Stress can kill a fish quicker than anything.

I did only about 30-40% 

The shop didn’t anything about doing it but I’d read it could be helpful near the end of the cycle. 
 

I think it might be stress because that Cory was super jumpy compared to the others and spent a lot more time hiding than them. 

On 4/1/2024 at 10:38 PM, Tlindsey said:

It's various reasons the one I've experienced is that the fish was not healthy although it looked healthy. 

I suggest not to add anything else to the aquarium.  I would wait for about minimum a month and hopefully things remain good. I would quarantine any other fish prior to adding in the future. 

Thanks for the advice!
 

Yep will do this, I’ll wait till everyone and everything is properly settled, and I know that none of the others have the same issue before replacing the Cory. 

[lefty o]

if none of the other fish show any odd signs, id write it off as a weak fish.