You could elevate the trough on an angle and use gravity to run water over it, you basically put a screen on the bottom for algae to grab onto and then run the water over it, and provide light.
The kinds of algae that will thrive here will provide massive nutrient export. Maintinance is essentially removing the algae which is easy to do.
It is kind of like a wet/dry environment, like the sludge that is in intertidal areas in the ocean. Huge public aquariums used this method for nutrient export for decades, though I suspect they may have moved on to something more high tech.
|