Reef Safe Tank JanitorsDetritus and uneaten food left in a tank create nitrates and phosphates which, in turn, feed microalgae. There are chemical and "natural" products available on the market which will alter or remove nitrates and phosphates, but they do not affect or remove the causes (detritus and uneaten food) of the excess nitrates or phosphates. Many of these products can not be safely used in aquariums with invertebrates and/or corals (reef tanks)
Reef Safe Tank JanitorsMechanical filtration can help isolate (for removal) detritus and uneaten food in an aquarium, as will vacuuming the substrate. Biological filtration processes ammonia produced by the rotting detritus and uneaten food, but you are still left with the resultant algae food (nitrates). Fortunately, there is a wide variety of reef tank safe (don't destroy other tank critters, corals or invertebrates) animals which thrive on the tank pollutants which create algae and other problems.
Reef Safe Sand Sifters
Sand sifters process the substrate surface, consuming algae, detritus and uneaten food without adversely affecting other organisms in the aquarium.