algae turf scrubber filtration

 Algae turf scrubbers (ATS) are a natural filtration method for removing excess nutrients like nitrates and phosphates from water. It is a simple combination of water, air and light that promotes algae to grow within a confined filter as opposed to the display aquarium. As the algae grows on a lit screen, it is periodically removed through harvesting and thus removing the excess nutrients from the system.

Algae turf scrubbers were developed in the late 1970’s when Dr. Walter Adey began using various species of algae to consume the unwanted nutrients in seawater. Dr. Adey’s initial design utilized a dump bucket to pour water over a bed of turf algae. Although very effective, this design was not conducive to the aquarium hobby as the ATS units were quite large, loud, messy and unreliable. Over the years as more interest with using algae turf scrubbers to filter aquarium systems, the designs started to change.

Current algae turf scrubber designs include two opposing designs; the up-flow scrubber and the waterfall scrubber. The up-flow design uses air bubbles to lift water up over a lit screen submerged in the water. The waterfall design has a pipe feeding water over a lit screen.

The waterfall design has quickly become one of the more popular and effective designs in algae turf scrubbers. These ATS units usually consist of an acrylic box that has a pair of LED grow lights mounted on two sides. The algae screen is connected directly to a feed pipe tucked into a slot cut in the pipe. When it is time to harvest the algae and clean the filter, the ATS unit is turned off and the feed pipe is disconnected from the ATS unit at a union fitting. The screen and feed pipe are lifted up out of the ATS unit and then cleaned and reinstalled into the ATS unit and the water flow is turned back on.