Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Even 3 Cories is not much of a group. I used to get them in 3s, but when I got more (minimum of 5) they were much more playful and up front.
I realize this could seriously affect the bioload in a small tank, so look for the Cories that are the right size:
The smaller dwarfs can be stocked half a dozen in a 10 gallon and still have bio-space for a mid tank swimmer like Dwarf Rasboras. Sure could not put half a dozen of the larger ones in a 10 gallon, though!
Monitor the NO3 levels. If they are holding stable, then do not worry about a little food that hits the floor of the tank now and then. No matter how little you feed the fish are always going to miss some.
If you see the NO3 climbing too fast, then feed less. The plants are not using as much nitrogen as you are adding to the tank.
Many people over feed the fish. Skip a feeding once a week (unless these are fry). Rotate different forms of food.
Feed high quality food. Not fish meal and grains.