26 Algae Scrubber

The Algae Scrubber is an open biofilter for the reduction (assimilation) of nitrogen (nitrate) and phosphorus (phosphate). The aquarium water flows over an inclined plane. On this plane is a mesh on which filamentous algae can settle. The surface must be illuminated. From time to time, the excess algae are scraped off the net mesh.

Just like a refugium, it can be lit at night and softens the daily pH fluctuations. The nocturnal oxygen deficiency in skimmerless aquarium systems is also reduced.