If your feeding live feeders then that is alot less mess and waste then if you are using pellets or something. If your feeding live and doing a 50% water change and vac every week i think you are fine. But if your feeding a pellet I would do 2 vacs a week.
I feed earthworms and shrimp and etc. They won't even touch pellets or etc. I've starved them for 3 weeks, I'm getting bored with the tank just putting in a few pellets and watch as nothing happens so all live for me or shrimp and etc.