Since some time this stuff is regulary a subject on the APD. Is it possible to refine conclusions? The questions I have: Is it possible the aq. plants do prefer ammoniUM and algae do prefer nitrate or even phosphate? Or do algae also prefer ammoniUM above nitrates or even phosphates? If the first is right, it should be easier to keep the algae out of the aquarium. Can someone refine this part of the subject? Gerard van Klaveren