10 gallon stocking idea

the 10g stocking list is fine. The 5g maybe fine, but as long as you research the species of cory you get in order to make sure you get a species that has an adult silze of 1-2", and you only get 3 cories all will be good.
 
The 10g setup should work well. Most cories like to be in groups of at least 5 of there own. You could go for the panda cories or the salt & pepper cories as both stay pretty small, about 1"-2" adult.

I would not suggest putting them in the 5g though. Most cories are pretty active and need more space then a 5g allows. You will see a big difference in activity if you only 3 cories versus 5. They simply will not be very happy with only 3. Most cories are a type of schooling fish and need to be in a group of at least 5 or more.
 
I agree with the statement above. cories need just a little more space than a 5g allows. if you really want catfish, you could try 2-3 otos. they are very cute and only get around 1-2", but be forewarned; they need a well-cycled tank as they are not very hardy at all.
 
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