Looking for some help, Corydoras: Peppered, Julii, or Habrosus

[superyogurt]

Hi everyone,

I have ten gallon tank that has already been cycled for two months. Current residents are a single Nerite snail and two Cherry shrimps. I'd like to get either three Peppered Cories, three Julii Cories, or 5-6 Habrosus Cories. The problem is that I know 10 gallon is a pretty small tank. I'm wondering if these numbers would constitute overstocking.

Will the Peppered Cories grow too big to be comfortable?
If these species are not appropriate, does anyone have any other suggestions? I'm mainly looking for hardy species that can be comfortable housed in a ten gallon tank.
I've heard that the Peppered Cories are the hardiest. Is this true?
I know Cories like to be in groups, are three individuals too small of a group?

My last concern is with the substrate. I know that sand is best for Corydoras, but I'm wondering if small sized round gravel will do. I have considered providing them with sand, but I dislike the idea of anaerobic gas buildup, and the difficulty in cleaning a sandy substrate.

Thanks in advance.

[toddnbecka]

Forget the 10 gallon tank and find a way to upgrade to (at least) a 20 long. When it comes to tank size, bigger is always better. If you can't get a bigger tank I'd go with the hasbrosus or one of the other dwarf species. Any schooling fish is happier in a larger group, and the dwarfs aren't as bottom-oriented as the larger species. They'll swim all over the tank, making better use if the available space, and generally be more interesting.
As for the substrate, sand is better. It's easier for bottom feeders to find food on top of the sand than down between gravel. Cleaning isn't difficult, particularly if you use a larger grade of sand (like pool filter sand) or a finer grade of gravel. I got some "gravel" at my lfs that I would have called "sand" personally, but it's much easier to deal with than play sand. If you don't make a thick bed of it you're less likely to have anaerobic pockets form. Stir it when you do a partial water change and you should be fine.

[gm72]

Toddnbecka said everything I was thinking. You won't see cory true behavior without a larger school. Otherwise, ditto!

[robflanker]

For my 10g, I'm planning on getting 6 dwarf corys or panda corys. But i'll be moving them all to a 30g in August.

See my sig for my planned 10g

[superyogurt]

Thanks everyone. Can anyone speak as to the hardiness of the smaller corydoras species? I've heard that habrosus and panda are a bit harder to keep than the larger ones. Besides habrosus, panda, and hastatus, are there other small cories I should consider?

[toddnbecka]

C. pygmaeus is also a dwarf species. I've never heard of them being more difficult to keep, just more difficult to breed. However, I'm not a Cory keeper. I prefer Synodontis and pleco's; Cory's don't mix well with most cichlids.

[troy]

I have some pygmy corydoras and they IME are just as hardy as the bigger corys.

[superyogurt]

Alright thanks for the advice, I think I'll get some pandas or some habrosus.