i feed the fish in my planted tank (cardinals, flying-fox, ottos, chain loaches, blue rams) twice a day; each feeding is very small.
my cichlids i feed sparingly, every second day i give them one feeding. the rest of the time they munch the algae off the rocks and back glass (i've been trying to get as much algae growth for them as possible).
generally i only give my fish as much as they can eat in 20-30 seconds, if they haven't eaten it after that, i give them one more minute and, if it's still there, i remove it using a net.