Feeding works in levels...
The fish eat the bulk and largest parts: They miss some, bits break off and they poop some out too.
Same then happens with the shrimps, crabs and snails.
Then the bristleworms, starfish, smaller worms
Then the copepods, isopods, amphipods, etc.
Then the bacteria
You want it so nothing is left unprocessed (which just rots).
Judging this by the top level, how much the fish eat within about 2 mins, is a good guide to getting it right.
Keep an eye of how quickly nitrate and phosphate rise. Rising quickly likely means overfeeding.