Cory's and Schooling

[raijevais]

I have a small 15 gallon tank. with the following lovely's in it:
1 Mystery Snail
3 Cory's:
1 Albino I have had about a year now
1 Panda and 1 Greenish/Grayish/ Blueish one I got at the same time about 2 weeks ago.
and a single Loach, he is slithery and brown.

I would like to add a few more fish and was thinking a Male Betta might make a visually pleasing addition as the tank is in my office at work and gets plenty of looky-loos.

But I recently was told that Cory's need to be kept in groups of 6 or more. My Panda and Albino are fairly active and will rest together at times.

The Loach and the other Cory like to share the same hiding spot, but I think it is just because they are both shy.

The Albino had been on his own in a Goldfish tank for a year now seemed to thrive. But we recently rehomed the Goldies due to their size and "Al" seemed to be very lonely and depressed.
He does seem to tolerate the panda more than seek him out, but they both seem to be doing well.

I am more worried about adding to the school and someone being pushed away.
I was told that mixing the Cory's would be fine and they will form a school, but I am doubting that advise (pet shop advise...) Should I get a few more of the Green/Gray guys to keep him company? Or do you think simply adding 1 more of each to keep the diversity will work?

It's a 15 Gallon Tank and I am hoping that 6 Cory's the Loach, Snail and Betta won't over crowd them.

Any Advise?

[Barliman]

It really depends on the personality of the betta: some are fine with tankmates, others turn into little serial killers -- I've experienced both. My only advice is try it if you want, but be prepared to separate or rehome the betta should he become a problem.

And, yes, corys do like to be in shoals of six or more. They'll feel more secure and engage in more interesting behavior.

[raijevais]

Do you have any thoughts on the types of Cory's? Should I get 1 more of each or do you think I should just get a few of the Emerald ones? I find him to be he most pleasing to look at but the Pandas do seem more inquisitive....
I just want to be sure am doing what will make everyone comfortable. and I am afraid if one little guy won't join the school that he will get bullied.

[skrapeNKA]

I'd add more of your favorite cory you already have. If it's the emeralds, add more of those!

[Barliman]

If you add more of the same species, they'll shoal together; different species won't necessarily shoal with each other. I'd get a few more emeralds.

[Autumnsky]

The wiggly Loach could be a Black Kuhli Loach which also like to live in groups.

The Panda Cory would probably like a couple friends, at least I would do one friend but 2 friends would be better. The Gray green might be bronze or green Cory and the Albino also these might be the same Corydoras aeneus.

Or the Green could be 'Emerald' Brochis Splendens, a slightly different and larger fish.