Avacado Man. The standard stocking number for Corydoras is one per every five gallons of tank water. Four small Corries would do well in a 20 G tank. They're generally bottom feeders and will help clean up the food scraps in your tank.

They're very peaceful and do well in most community tanks. Keep two or more together. I have a number of different varieties and they all swim together.

B

__________________
Low Tech Water Building Keeper