Sterbas Cory strange behaviour

[Chaines1991]

Hello.

I have a 150 litre aquarium with a co2 system , live plants and a number of tropical fish species including 5 sterbas corydoras.

Last week I unfortunately lost one of my sterbas , after inspecting the tank and the body I could not find any issues that could explain his death. Since then I've been watching the tank closely for any signs of infection , tonight whilst feeding I noticed one of my sterbas spending a lot of time taking air at the water surface , after a while he will swim down to the bottom and behave normally grouping with the other sterbas and then a few minutes later will swim back to the surface. I haven't noticed this kind of behaviour before I am thinking of transferring him to my quarantine tank however it is currently going though a bacterial bloom and I'm not sure if it is safe to transfer him to the tank.

No other fish appear to be showing symptoms or signs of infection , last week I performed a water the test the results were as follows :

P.H - 8.2
Ammonia - 0 ppm
Nitrite - 0 ppm
Nitrate - 5 ppm

Any help on this one would be most appreciated.

Many thanks!



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[sinibotia]

pH is pretty high, do you have any idea of the hardness of your water or what that is?

Aside from that, gulping air from the surface is actually a normal corydoras behavior. They're known to dart to the surface and gulp air. Unlike fish like bettas who have a special organ for breathing air, corydoras just pass the air through their digestive tract and absorb the oxygen through the lining of their intestine

 

[Chaines1991]

pH is pretty high, do you have any idea of the hardness of your water or what that is?

Aside from that, gulping air from the surface is actually a normal corydoras behavior. They're known to dart to the surface and gulp air. Unlike fish like bettas who have a special organ for breathing air, corydoras just pass the air through their digestive tract and absorb the oxygen through the lining of their intestine

My water hardness is about 10 dkh/179 ppm

I switched to RO water some time ago before I got the sterbas

Hope this helps


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[sinibotia]

That's just your KH? That seems really high to me. Might be causing them stress. Hopefully someone else will chime in and let me know if I'm way off base

 

[Chaines1991]

That's just your KH? That seems really high to me. Might be causing them stress. Hopefully someone else will chime in and let me know if I'm way off base

When I set up this tank I tried to establish a mean/average hardness based on all the requirements of my fish , I did do plenty of research on this but thanks for the input.


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