Cory Group Sizes And Alternatives

[JezTaylor]

Hi all,
 
I'm looking to get a few bottom dwellers for my 64l tank. It seems that cories are the most popular option, but I have a couple of queries.
 
Firstly, group sizes. I've seen some people say that they should be kept in groups of at least 4 and others say you need at least 10 for them to be happy. Given the size of my tank, 10 would leave me very little room for any other fish. Do any Cory experts have views on this?
 
Another issue is that I have quite course gravel on the bottom of my tank and I've read that cories prefer sand or smooth stones. If I were to put a few smooth pebbles on the bottom of my tank would that do the trick, or do I need to go further?
 
If they do need to be in larger groups, can anyone recommend some small bottom dwellers that would be happy in a group of 3 or 4?
 
Thanks for your advice!

 

[the_lock_man]

With cories, as with all shoaling fish, the bigger the shoal, the better. In the wild, they live in shoals that are hundreds, maybe thousands, strong. It is generally accepted, certainly around this particular corner of the intertwittyweb, that 6 is the point at which they lose count and assume it's a wild-size group.
 
There are 2 species I would recommend for you. Corydoras Habrosus and Corydoras Hastatus. Both of these are dwarf cory species, so will minimise the impact on your stocking capacity. There is a 3rd similarly sized species, Corydoras Pygmaeus, common name Pygmy Corydoras, but I've found that these for some reason seem to like the mid-water section, rather than the bottom.
 
Cories feed by snuffling around in the substrate looking for food. If the substrate is coarse, it wears away their barbels. Just bunging a few smooth pebbles down won't be enough, because they won't restrict themselves to just that area. Far better to replace the substrate completely with sand. Even smooth gravel isn't quite what they need - though it is better than coarse.

 

[techen]

Corys take up ground space, Not mid to high swim space. So if you got 10 corys, you still have free swimming spaces in mid and top!
 
6 Corys is what I would say min is for a good group, 10 is more than fine.
 
You want a sand bottom for the tank, Smooth pebbles would work but they love sand as they shift through it.
Lock man always beats me

 

[JenJ]

6 is a good number, and sand is preferable as the cories will sift through it

 
It's quite easy to change - just a few pounds for some sand and an hour or so of your time.
 
Your tank would be fine with 6 and a few other fish in the upper levels.

^ hmph. they both beat me.
 
Is there any particular type of cories are you after? I'm looking to rehome 6 fairy cories if you're near Surrey way.

 

[the_lock_man]

Lock man always beats me

 
Sorry, Techy. 

 

[JezTaylor]

Thanks all for your advice. Looks like 6 and sand is the way forwards for me. Of the three minuature breeds I've seen (hastatus, habrosus and pygmaeus) I think it's the habrosus that I fancy, though I'll have to see what I can get locally (afraid I'm not too close to Surrey). The one that I've seen plenty of in local stores are the albino cories, but I presume they get a bit bigger?
 
Out of interest, are there any other types of catfish that would be suitable or do they all like larger groups and sand?

 

[the_lock_man]

Albino cories do get a bit on the big side for your tank. Pretty much every type of catfish prefers sand, for that same reason, really.
 
I had a shoal of c.habrosus at one point, and still have the last one, who survived a massive whitespot outbreak. Fantastic little fish, really lovely to watch them playing together. I got them from a LFS near Southampton, if that's anywhere near you.

 

[daveg6529]

6 Pepper Corys would be ok I have 10 in my 260ltr with coarse gravel and they seem to do fine.
Sand is much better though. 
Midwater wise I have 6 glass catfish. they all get on well.

 

[Sophie]

I have 12 Sterbai's of various sizes. They love playing together and make little conga lines when it's feeding time :3

I got them from a LFS near Southampton, if that's anywhere near you.

Too close for comfort only a few mins down the road from me!