Most people incorporate refugium to grow algae of various kind, and harvest algae either as food for herbivores or trimming them on regular basis as nutrient export. Refugium has added bonus of breeding various micro fauna and copepod/amphipods which will be a great source of supplemental nutrient for reef fish.
Use the "search" feature in the heading section of this BB, and type in "refugium". You should have hundreds of threads to browse from to read.
