Trouble with corydora

[Holm_Tanks.]

Hey I've had some corys in my tank for a little over a week and for the first 6 days no problems. But during the last 2-3 days one of them is discolored (very pale) and he'll sit on the bottom of the tank for minutes at a time. I can see him breathing and I don't see and spots. Does anybody know what's happening? I need help.

 

[Stefan3289]

Could you give first:
- Water reading- ammonia, nitrates, nitrites, ph.
- Do you have enough water surface movement (to allow oxygen through)
- What is the temperature of the water
- What kind of Cory do you have
- What is your cleaning schedule like

 

[Stefan3289]

As for his breathing:
- Is it heavy or rapid
- does there seem to be any slimy or thick stuff on or around his gills
- Is he the only one you happen to see with symptoms or do you know for certain it’s only him

 

[Holm_Tanks.]

I don't have a test kit on hand I used my last one last week. All the surface movement I have is from my spray bar (should I use the single jet instead) the water is 71 degrees. The are bronze corys. I do a fifty percent water change once a week and vacuum the gravel at the same time. There is no slime on his gills. He has the worse symptoms if not the only one. He is very pale and the others are not. The others also stop and sit but they do it very briefly like a second. Compared to him where he sits way longer.

 

[Holm_Tanks.]

How do I post videos to show you

 

[Colin_T]

Post clear pictures of the fish.

Check the water for ammonia, nitrite. nitrate and pH. Post results in numbers here.

Do a 75% water change and gravel clean the substrate every day for a couple of weeks or until we work out what is going on.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Upload video to YouTube and then copy & paste the link here

 

[Holm_Tanks.]

 

[Holm_Tanks.]

I might have found a problem, the output on my canister filter isn't near as strong as it used to be. There must be a clog or something slowing it.

 

[Colin_T]

do water changes and gravel clean the substrate

 

[Holm_Tanks.]

I do once a week already how often do you suggest?

 

[Holm_Tanks.]

Should I quarantine him?

 

[mark4785]

How did you prepare the aquarium for the Corydoras? Is this a new aquarium?

The reason I ask is because it can take about 5-8 days for ammonia to become detectable in water at the kind of temperature you have and i take note that you say problems occurred 8+ days after they were introduced.

I would presume you have elevated ammonia and do a 100% water change.

 

[Holm_Tanks.]

It is not a new aquarium it was a month and a week old when I introduced the corydoras. I let the aquarium cycle (at set up I put prexisting bio-filter media from another tank) I waited a month and then checked the water parameters for two weeks after the month and they were stable.

 

[mark4785]

It is not a new aquarium it was a month and a week old when I introduced the corydoras. I let the aquarium cycle (at set up I put prexisting bio-filter media from another tank) I waited a month and then checked the water parameters for two weeks after the month and they were stable.

The parameters would be stable without fish excretions and food in the water column during the month you mention. I think you might be dealing with a slightly elevated ammonia and nitrite issue in response to the sudden higher stocking level of the aquarium.

Do you see the corydoras flashing off of any objects?

 

[Holm_Tanks.]

Why wouldn't all the fish be doing the same thing they were all introduced at the same time. I'm gonna do more frequent water changes like recommended. I don't know what you mean by "flashing off objects"