Euglena sp. Not the same as "water with a lot of algae in it". Virtually all aquarium "grey water" or "cloudy water" when you look at it is just lots and lots of green filaments of algae is not generally the "bacteria" we think it is; you don't need a microscope to look at this, a hand lens will make this very plain. Euglena is a microorganism that has characteristics of both plants and animals. Like swimming algae with a mouth that eats smaller bugs as well as photosynthesises. You usually have to buy these as a pure culture, it's not easy to isolate them from pond water or a fish tank even if they are actually present. Any decent biological or scientific supply house will sell them.
