Originally Posted by musho3210
Originally Posted by tophat665
...Small Corydoras (C. Pygmaeus, Hasorus, hastatus, panda) - 5 - 10...
The above is the amount if that is all that is in your tank....
5-10 cories is too much for a 10 gallon, unless its a species tank 3-5
That's why the species I listed. C. Pygmaeus, hasborus, and hastatus stay 1" to a shade over, and C. panda tops out at 2". The first three can be kept in the same sort of densities as the smaller tetras. Pandas need a bit more room. Surely, though, 5 (pandas) -10 (pygmaeus, hasbrosus, or hastatus) in a 10 gallon is well within the carrying capacity. These are not the same things as C. aeneus, or Brochis Splendens, which get around 3" and should not be kept as more than a pair in a 10 gallon (if at all. And please forebear to remind me that cories prefer shoals; there is disagreement on that point, though I prefer them in shoals myself.) To top that off, the fist three listed cories are less wedded to the bottom of the tank than most, and are frequently found schooling in midwater under the proper conditions, so issues of tank floor space are less germane for these than larger species.
Let me round this out a little more. There are at least 5 dwarf species of corydoras. Corydoras pygmeaus (Pygmy Cory), C. hastatus (Dwarf Cory), and C. hasbrosus (note: misspelled in orignal post) are fairly commpnly found in better fish stores. C. cochui and C. guapore are also in this group, but much, much rarer.
All of these are tiny, maximum length from 1 to 1.6" (2.5-3cm). All prefer to be in a larger school than larger cories (6 minimum, 10 better, 50 or 100 or more better still; there's no argument that these are schooling fish). All spend more time in midwater and like to rest on leaves of aquarium plants (they really prefer a densely planted tank - I sometimes see my Pygmy Cories resting halfway up the cabomba thicket in their tank). They are entirely peaceful, and should be kept only with other small, peaceful fish (msmall carachins like neons are ideal). Scotcat.com says that 10 gallons is ideal for a shoal of 8 C. hastatus (or 6 C. panda), and mentions breeding C. hasbrusus in a 5.5 gallon. They require small foods (brine shrimp, powdered flake, tubifex). They have a relatively wide range of water tolerance: pH 6-8, temp 72-80, and GH 5-19.
Panda cories are a little bigger, a more inclined to the bottom, and less needy of large schools (though 6 is still a good minimum number)
Finally, these little fellows are occasionally stocked in award winning planted tanks of as little as 1 gallon.