Newbie question: Are my corydoras "glass surfing"? Is this normal?

[DaPrawf]

Three of my 5 orange Venezuelan corydoras have been doing this all day for several days. Is this what they call glass surfing? Is it normal? The corner they swim in is the one next to the HOB filter outlet and closest to the air stone.

It's a 29 gallon tank. Tested today: Ammonia 0 PPM. Nitrite 0 PPM. Nitrate 10 PPM. pH 7.4. Temp 76.8. Smooth gravel substrate.

Other fish are 1 honey gourami and about 12 green neon tetras. I read recently that a shoal of cores should have at least 6 fish. Should I get another?

Edited August 21, 2022 by DaPrawf
added more information

[Ken Burke]

Very normal!  
 

They look young to me.  If the are adults looks for eggs on the glass

 

corydoras glass surfing can just be juveniles playing, or males trying to get a female to spawn.  

 

[Kurt Brutting]

My Panda Cory’s glass surfed for the 1st or more. I was worried, but eventually they stopped and now they are just happy little catfish. 

Spelling correction - I meant to write 1st week or more.

[nabokovfan87]

Very very very very typical behavior.  It's usually a sign of a few things, all of them good.

-Playing in the flow (my pandas do this pretty much 24/7 all day long), happens a lot with corydoras
-Looking around for food
-Breeding Behavior

-Following the others that are playing in the flow (shoaling behavior)

Here's one of my black Corys doing the same thing

 

On 8/20/2022 at 6:12 PM, Ken Burke said:

They look young to me.  If the are adults looks for eggs on the glass

You can also see who is doing it, look for eggs held in the fins.  Ken your photo is awesome!  How are yours doing?

[Cinnebuns]

Not only is it common behavior for cories but especially near an area of high flow like is being created by your filter and air stone. They love it!!

[Ken Burke]

On 8/20/2022 at 9:42 PM, nabokovfan87 said:

You can also see who is doing it, look for eggs held in the fins.  Ken your photo is awesome!  How are yours doing?

Mine are doing so well. The egg picture is from this morning…..

[nabokovfan87]

On 8/20/2022 at 7:59 PM, Ken Burke said:

Mine are doing so well. The egg picture is from this morning…..

I figured it was recent, awesome stuff.  Best of luck!

[gardenman]

Glass-surfing is perfectly normal. I have a suspicion it's related to migration in some manner. Mine always seem to glass surf towards the southern wall of the tank.  It's like they're driven to swim south and run into an invisible wall that stops them. Some fish do migrate to spawn or for other reasons and I suspect that's what drives glass surfing. Every instinct they have says "Swim that way!" and they try to only to hit the glass wall and can't find a way around it.