"The turf algal communities of coralgal reefs are master primary producers in nutrient-poor seas. Composed of assemblages of many species of cyanobacteria, as well as red, green and brown algae, the filamentous turf algae with their high surface area to volume ratio are highly efficient at stripping the nutrients nitrogen and phosphorous out of the low-nutrient seawater. This was recognized four decades ago when public aquaria in the tropics started using turf algae to reduce the high nutrient loads delivered in aquarium seawater in the excreta of the resident fish, sharks, rays, and turtles. During the daylight hours, the aquarium seawater is pumped continuously on the sunlit roof of the aquarium, where it runs over turf algae grown on a series of corrugated panels. Resembling the washboards of old, the panels are placed in troughs to catch the seawater, which is then returned to the aquarium.
Turf algae are far more efficient at stripping nutrients from seawater than any known chemical method, and is also a cheaper, natural, and nonpolluting method for the aquarium. Another benefit is that the excessive algal growth is regularly scraped off the panels to maintain the high growth rates, providing the resident herbivorous, green turtles in the aquarium with a meal of delicious turf algae."
- The Lives of Seaweed, page 184
Turf algae are far more efficient at stripping nutrients from seawater than any known chemical method, and is also a cheaper, natural, and nonpolluting method for the aquarium. Another benefit is that the excessive algal growth is regularly scraped off the panels to maintain the high growth rates, providing the resident herbivorous, green turtles in the aquarium with a meal of delicious turf algae."
- The Lives of Seaweed, page 184

