Must a "mixed reef" contain corrals? A reef aquarium setup is always a mix of life but must it always be based on LPS /SPS? A normal reef is always a mix of vertebrates, invertebrates , phytho. For me a " mixed reef" is a normal reef setup always including vertebrates, a display of reef fish and their normal habitat. Makazi Baharini. A " mixed reef" is a high nutrient system needing an other approach for keeping LPS/SPS,It seems now the term ‘mixed reef’ is thrown around, I see LPS/SPS reefs classed as Mixed, I’ve seen LPS/Softies classed as Mixed. But a mixed reef, does it mean you’re varying with RSWC fish as well as having all 3 types of coral, is it just having the 3 types of coral or is it only having 2 types of coral?