the only real way to remove detritus is through siphoning during water changes and vigorous skimming. there are critters that will eat leftover food stuff, but they will not actually eat end detritus. these critters include sea cucumbers and
Cerith snails. Nasarious snails will also, but they tend to want bigger chuncks.
detritus can come from various sources. it can come from the LR, bacterial turgor of the phosphates in the LR. it can also come from critter poo. this is why it is important to only feed what is necessary.
G~
