I would really like to add about 6-8 dwarf Corys to our 75 gallon tank. I really like the Cory Habrosus, but have heard it is not very hardy. Which of the smaller Corys are the hardiest that you would recommend? They will be in a planted tank with Eco Complete substrate topped with a layer of sand. Tank mates will be Endler Livebearers and Neon Tetras. Maybe a few Golden Pencilfish.