Filamentous, slime, smear, and macroalgae are highly efficient at absorbing such material, and they grow rapidly. In most circumstances, the microalgae and macroalgae, while very useful as part of turf scrubbers or small algal communities within a reef, often become problematic as they overtake the more aesthetically and, in some ways, functionally desirable crustose red algae (coralline), corals, and other sessile invertebrates. It should be noted, though, that these organisms might also be capable of significant nutrient uptake. Bacteria and phytoplankton are also extremely proficient at removing this material. All these organisms are quite valuable to our captive reef communities. They not only "purify" water by the utilization of nutrients, but also are all part of a beneficial food web, both in coral reefs and in aquariums.