Will my cories school together?

I have a relatively new cycled tank, and I have just added 5 cories (after having 4 platies). I was thinking I would get all the same kind of cories, but on the last minute decided to get 3 julis and 2 emeralds. The woman at the store said they would school together, but they seem to be "segregating." Will they figure it out or do I need to get more of each? I have a 28g hex tank, so I was really thinking I needed to keep it to a small school. I am planning on adding 5 serpae tetras, and that will be complete.

 

Hi,

From what I have read emerald cories will not school with juliI cories as a rule. Cories may school with other species if they are lonely and there is no other option (no others of their own species), but cories do prefer their own kind.

It is my understanding that the 28 gallon hex is more tall than it is long. Since cories require a good amount of floor space, the hex may actually not be a good habitat for most Cory species except for dwarf varieties. Neither juliI nor emerald cories are small - in fact I think the emerald green are larger than many other Cory species. Therefore, adding more to the school is not really an option for you. Could you return and exchange them?

 

Hmmm.. I could see about returning the 2 emeralds and getting 2 more juliis. I know I can get money back if they die, but I don't know the return policy. It was Petco, if anyone has any idea about that. (There isn't a LFS near me, and the Petco fish seem to be much healthier than Petsmart.)
They do seem to be "mingling" with the juliis a bit now though.
The tank is more tall than long, but the cories seem to be having fun darting up and down. I have had cories before (in a 10 gallon tank) and they seemed to do this a lot. I always assumed (read?) that it was a playful type thing, not a stressed out thing. Is that not correct? I know that they are bottom feeders, but since I had previously experienced them to dart up and down a fair amount, I figured they would be okay. (I did plug it into aqadvisor also. That was where I saw that they preferred to school with the same type of cory.) My plan originally was to get all of the same, but I ended up changing my mind when I got to the store.

 

Hello and to FishLore!

PetCo will take them back. (I returned a platy about three months ago). You might have more fun with 5 juliis than two emeralds!

Yes, cories do school with their own "sub" species. And in my experience, with albino cories, they love to swim all over the tank. It's like they are playful puppies just dashing all over the place! I have three in a 5 gallon hex with a platy, and they are happy. IMO as long as your tank is not overcrowded, and your water chemistry is good (nitrogen cycle), and your fish are healthy and appear happy, you are doing well.

 

Thanks! I ended up taking the emeralds back and got 2 more Juliis. I have been going to aqadvisor, and I wonder about overstocking a "little" as long as I have adequate filtration and do recommended water changes.
Thoughts?
Right now, I have 4 plates, 5 JuliI cories, 1 mystery snail and a tiny ghost shrimp. I plan on adding 5 serpae tetras, but would love to add 1-2 more Juliis and a dwarf guarami. That would put me at 117%, but I still have 140% filtration and would need to do 24% water changes weekly.

 

Emerald "cories" are not actually corydoras catfish. I believe different colors of cories will school together.

If you are getting those stocking percentages from AquAdvisor, take them with a grain of salt. They do not take into account, for example, the fact that cories are bottom-dwelling fish and prefer a larger footprint.

 

So, what are you saying regarding the stocking? More than 5 cories would be too many for my 28g hex?