Corydoras swimming up the surface

[Celine]

Hello,
It has been a couple of weeks since I have noticed one of my bronze corydoras (I have him for about 4-5 years now) swimming on top of the tank and often taking breaths. It is the only one of my corydoras who act like this(I have 5 in total). The others mostly stay at the bottom of my tank and swim up to catch a quick breath.
I have checked my tank parameters again today and my readings show:
Ph: 8
Nh3: 0
No2: 0
No3: 5
Kh: 4 (maybe a bit low?)
Gh: 8

For the kh I also tested my tap water and the result is 4. Do I need to add a Kh buffer?

Would you have any idea why my Cory is often at the top level of my tank taking breaths? I have added an air stone in my tank with no improvement and my fluval pump is making a small current at the top.

My tank is also planted with java fern, crypto, anubias and another background plants which sadly I do not remember its name. I have add about one squirt of tropica fertilizer every week and it is a 64L tank (dosage on the bottle says 5 squirts for a 100L so I am well under that too).

I would really appreciate your advice!

you!
Céline

 

[Guyb93]

I know corys dive bomb a few of mine will swim take a gulp of air and swim back down do you have an air stone or an external filter that disturbs the water enough , ph seems rather high for corys I think could be wrong I know Gh is the ticket but ph of 8 seems high

 

[Celine]

Thank you for your message. At the moment, I have an air stone and an internal fluval filter which creates a current on the surface. I don’t have an external filter.
The behavior you describe is exactly the same as my other bronze cories (they were added 1 month ago). I also have another Cory, a Julii, aged 4-5 years old too. The Julii Cory is much quieter,he mostly swims at the bottom of the tank looking for food.
Only my 4-5 year old bronze Cory swims at the top of the tank and often comes to the surface to take breaths.
As for the PH, I agree it is a bit on the high side. I have already added some driftwood but it does not seem to have moved since adding it to the aquarium (I added this a month ago). What would be the best way to lower the PH naturally?
Thank you !

 

[Phreaker]

No need to change your PH, especially considering they have already lived in it for years.

 

[AilyNC]

PH is fine for Bronze Cory actually. Not sure about the the others.

I don't have any that cruise up top - only the dive bombing.

@NCaquatics is a cory guru.

 

[CassCats]

My aeneus go all over the tank and ive had paleatus that learned to go up top to look for food too.

But first, are their gills red at all? Any gasping? Heavy breathing? Scratching against anything? What do you use for oxygen?

 

[Essjay]

And you don't need to alter the KH either.

 

[Celine]

Thank you for your message.
I use an air stone and the fluval internal filter which moves the water surface. Is there any other way to increase the oxygen in the tank?
As for the gills, I think they look normal, slightly pink maybe. I have tried to take a picture of the fish. Thank you

 

[CassCats]

Another thing... are they doing it mostly in higher flow areas?

I find prespawning some of my girls do this too.

 

[Celine]

Thank you for your reply. I have noticed he does this around the pump sometimes but also in different spots of the aquarium.

 

[jonny-5]

All my Bronze go to the top prob just as much as they are on the bottom. They dig in the sand, Throw it everywhere & fly to the top for a gulp of air, Then they rest under the bogwood for a while. Then it all starts again, They are all over the tank until lights out

 

[FishGuest5123]

One of my 5 week old bronze Cories constantly plays in the air stone bubbles. He’ll fly into the bubbles, then to the top, then dive bombshell to the bottom just to start over again. The only time he stops is to eat or sleep.

 

[Gypsum]

One of my CW045s and a C. schulzei frequently swim around the top, like in the OP's photo, but only after feeding time. The tetras are pretty rubbish at taking food from the water surface -- they grab it as it sinks downwards -- and the other corys and raphael cats scoop up food from the bottom. I reckon those corys have worked out that there is free and easy food floating around on the surface and no one to argue with over it.

 

[Gypsum]

One of my 5 week old bronze Cories constantly plays in the air stone bubbles. He’ll fly into the bubbles, then to the top, then dive bombshell to the bottom just to start over again. The only time he stops is to eat or sleep.

My C125s seem to enjoy swimming straight into the powerheads and then getting launched across the tank. They will do this over and over. Can't argue with them -- it looks like fun.

 

[ellamay]

How many corys do you have in your tank? And what other fish do you have in there? I've been looking at a 64l for corys, I don't have any fish yet just researching