the_deeb;3650491; said:
Interesting. This is probably largely irrelevant to the current discussion, but wouldn't this would imply that since phagomixotrophic algae could acquire nitrogen by phagocytosing other organisms rather than just consuming ammonia/nitrite/nitrate they may actually be less useful in the context of algae scrubbers (since the goal of a scubber is really only to reduce free sources of nitrogen - we generally don't care about the nitrogen that has already been incorporated into bacteria etc.)?
Phagocytosis is generally looked at as a way to import carbon rather than nitrogen, so phagomixotrophs could be effective at consuming N in CO2-limited environments where other algae might be more constrained. I have no idea how this would play out in the context of a scrubber, I just thought it was interesting.
With regards to freshwater systems, eutrophic systems (which is basically what a heavily-stocked aquarium is) tend to have high levels of both plants and algae. The more consistent the nutrient level is, the larger the plant portion. Boom-and-bust type systems often have more algae. Algae are also better-suited to high-flow and pelagic systems, and so tend to outnumber plants in those environments.
Algae biomass tracks closely to nutrient levels, so algae is better able to respond to sudden abnormal nutrient influxes (such as, say, a fish die-off, or Junior dumping a bunch of fish food in the tank) while plants are more persistent and so are ready to uptake nutrients after a long period of low nutrient levels, when algae populations may have crashed. So, there are possible benefits to using both plants and algae in a filtration system.
