Fish Breathing Trouble

HI everyone, I've got an albino cory catfish that I've had for nearly 6 months who's all the sudden started breathing from the surface, I'v had two other ones in the past who started doing that until they turned almost translucent and died. I test my water weekly, it's a 20 gallon tall tank with 6 cory catfish, 5 male guppies, 2 female platies, a horned nerite snail, and an amano shrimp, this tank probably sounds a little overstocked but my test results from this morning were ammonia 0, nitrite 0 and nitrate 10-15 and I have lots of biological media and live plants. Like with the other two cories this one is the only one who appears to be affected. Also I have an air pump and my filters give plenty of surface agitation. Is there something else about my water that could be affecting the cory, I know my ph is a little high, could that affect anything? I really want to know what's causing this , so I can stop it from happening.

 

No salt?

 

HI everyone, I've got an albino cory catfish that I've had for nearly 6 months who's all the sudden started breathing from the surface, I'v had two other ones in the past who started doing that until they turned almost translucent and died. I test my water weekly, it's a 20 gallon tall tank with 6 cory catfish, 5 male guppies, 2 female platies, a horned nerite snail, and an amano shrimp, this tank probably sounds a little overstocked but my test results from this morning were ammonia 0, nitrite 0 and nitrate 10-15 and I have lots of biological media and live plants. Like with the other two cories this one is the only one who appears to be affected. Also I have an air pump and my filters give plenty of surface agitation. Is there something else about my water that could be affecting the cory, I know my ph is a little high, could that affect anything? I really want to know what's causing this , so I can stop it from happening.

Have you noticed any type of red blotches on them or even any shredding of the fins?

 

No salt, no blotches and fins look fine

 

No salt, no blotches and fins look fine

It's strange that both of th species gasping for air are the 2 that have auxiliary breathing methods. They're supposed to take in air bubbles occasionally, but not gasp for air. You haven't added any Bettafix medication lately have you?

 

When you say they breath at the surface, what do you mean? Do they dash up to take a gulp of air and go back down every once in a while?

 

When you say they breath at the surface, what do you mean? Do they dash up to take a gulp of air and go back down every once in a while?

Yes

 

Yes

The betta has a a breathing apparatus in it's head called a Labyrinth organ. They will actually drown if the can't get to the surface once in awhile. The cories swallow a bubble of air and extract the oxygen in their gut.

 

Yes

That's normal corydoras behavior. I don't know why your previous corydoras died after it. May have been a water issue at the time or something else. You may catch your other corydoras doing the same once in a while, because as I said before, it's completely normal. Are there any other symptoms or is this behavior all that's happening? Everything seems overall fine in your tank. Feel free to increase surface agitation just in case, but I wouldn't bother.

 

Ok, I'm a little confused now as I never mentioned betta fish, my bettas are perfectly healthy each on their own tanks... my water has consistently be 0,0 and readable nitrates that a weekly water change maintains quite well. I've never used bettafix. I know cories will come up for a moment and take a quick gulp but my issue is them staying at the top taking continual gulps then going down acting fine and repeating the process. Thanks for the help

 

Ok, I'm a little confused now as I never mentioned betta fish, my bettas are perfectly healthy each on their own tanks... my water has consistently be 0,0 and readable nitrates that a weekly water change maintains quite well. I've never used bettafix. I know cories will come up for a moment and take a quick gulp but my issue is them staying at the top taking continual gulps then going down acting fine and repeating the process. Thanks for the help

I think they were just making a comparison.