As recommended by some Corydoras keepers, I am feeding mine Hikari's algae wafers and carnivore tablets. I've personally used Hikari food exclusively for all my fishes (except shrimp) and I always get good results with it.
I am feeding 1 algae wafer in the evening and 3 carnivore tablets in the morning. They adore the carnivore tablets, reminds me of kids eating french fries, they simply go crazy and see who can eat the most.