I bought 2 south american bumble bee catfish( Microglanis iheringi) on Monday. They have been eating very well. They ate two of my 0.5" cardinal tetras but that is beside the point. I have also been feeding them Hikari carnivore sinking pellets after the lights go off. I do not want to over feed them. They are the only bottom dwellers in the tank and I do not plan on getting anymore.

How many pellets should I be dropping in for them?
How often do I feed them?