Salt & Pepper Pygmy Cory is acting weird- constantly gulping for air

[enfiskejer]

I have a 110L low-tech planted tank with 3 Corydora Hasbrosus (I'm going to buy more but they didn't have anymore where I got them), 4 sparkling gouramis and a school of cardinals. One of the cories came without barbels, I've been making sure that he gets enough to eat but a few days ago he started staying around the top of the tank taking a gulp of air from the surface every 2-3 minutes.
I know this is 'normal' but it seems a bit suspicious, none of the others are doing it and it is staying near the surface at pretty much all times. I have a canister filter that has good flow and live plants so there should be enough aeration in the water right?
I will do a water test tomorrow and I haven't fed them today because I fast them once a week.

Is this something to worry about?
Does anyone have any ideas about what I can do?

 

[outofwater]

The lack of barbs and the staying near the top aren't exactly normal. Most cories, if not all I suppose; do that quirky gulp of air occasionally, but not constantly. And staying near the top is definitely not in their nature.

What do you have for substrate?

Is he eating normally? Does it look skinnier or fatter than the others? Are the gills reddish? If you could post a picture or a short video of it it would help better understand what could be going on for him.

 

[enfiskejer]

The lack of barbs and the staying near the top aren't exactly normal. Most cories, if not all I suppose; do that quirky gulp of air occasionally, but not constantly. And staying near the top is definitely not in their nature.

What do you have for substrate?

Is he eating normally? Does it look skinnier or fatter than the others? Are the gills reddish? If you could post a picture or a short video of it it would help better understand what could be going on for him.

I have pea-ish sized gravel that I gravel clean weekly and it isn't sharp. He hasn't eaten anything today (its morning right now), their sinking pellets still haven't really been touched. I drop their pellets on this flat slate rock so they can easily get to them so the food doesn't fall between the cracks of the gravel.
I don't think he looks skinnier or fatter, they look the same. The gills aren't red and I tested the water this morning, pH 7.6 (same as usual), ammonia 0 and nitrite 0.
He's still doing it, I have a breeder box should I put him in there and make sure he gets some food? Or will that just stress him out more...

 

[DragonScales+Doubletails]

I have pea-ish sized gravel that I gravel clean weekly

do you mean gravel siphon, or like remove and actually clean it?

 

[itiwhetu]

pH of 7.6 is really too high for these fish to be happy, they like slightly acidic water.

 

[itiwhetu]

What is your nitrate reading on this tank?

 

[enfiskejer]

do you mean gravel siphon, or like remove and actually clean it?

Gravel vacuum of course! Sorry my mistake
I read that they lose their barbels from an infection and if you have gravel it needs to be gravel vacced weekly.

 

[enfiskejer]

What is your nitrate reading on this tank?

I unfortunately can't test for nitrates as my nitrate tester doesn't work but I did a 35% water change 3 days ago so it shouldn't be too high.

 

[enfiskejer]

pH of 7.6 is really too high for these fish to be happy, they like slightly acidic water.

I bought them at a local fish store that got them from a local supplier so they have been in the same pH their whole lives but I understand it may be too high

 

[itiwhetu]

I unfortunately can't test for nitrates as my nitrate tester doesn't work but I did a 35% water change 3 days ago so it shouldn't be too high.

I have always thought that nitrates at any level are not good for Cory's.

 

[itiwhetu]

I bought them at a local fish store that got them from a local supplier so they have been in the same pH their whole lives but I understand it may be too high

Sometimes keeping fish in conditions that are not ideal is fine, but eventually they succumb. And you get fish that just fade away, like this one.

 

[enfiskejer]

Sometimes keeping fish in conditions that are not ideal is fine, but eventually they succumb. And you get fish that just fade away, like this one.

I read on seriously fish that they an tolerate 5.5-7.5pH so I assumed mine would be fine at 7.6 but if you think that's the problem what would you do next?

Corydoras habrosus – Salt and Pepper Cory — Seriously Fish

www.seriouslyfish.com

 

[itiwhetu]

Can you post a picture of the whole tank, so that I can get a feel for it.

 

[itiwhetu]

I read on seriously fish that they an tolerate 5.5-7.5pH so I assumed mine would be fine at 7.6 but if you think that's the problem what would you do next?

Corydoras habrosus – Salt and Pepper Cory — Seriously Fish

www.seriouslyfish.com

This is part of the new age of fish keeping, we now have sites that state fish will live in a range of pH's. In the olden days the books would say pH 7 for your fish and we would work 0.2 on the scale either side of that. Then with a little experience we would know a fish like yours preferred slightly acid conditions so we would work with that. Some of the other cory's like the pH at seven or slightly above. I feel that the ranges that are given on these sites are far too broad and that they need to be narrowed done some what.

 

[enfiskejer]

This is part of the new age of fish keeping, we now have sites that state fish will live in a range of pH's. In the olden days the books would say pH 7 for your fish and we would work 0.2 on the scale either side of that. Then with a little experience we would know a fish like yours preferred slightly acid conditions so we would work with that. Some of the other cory's like the pH at seven or slightly above. I feel that the ranges that are given on these sites are far too broad and that they need to be narrowed done some what.

Yeah, understandable. I am really new to tropical fish keeping.