Did you know that spirulina is actually just pond scum? This health food that seems to get more and more popular is a blue algae that is sourced from freshwater lakes and ponds. It is what we get when we clean our ponds. This blue green algae is native to Mexico and Central Africa. It is an ancient health food that was popular even among the Aztecs. Health aficionados love the smoothies and salads that contain this beautiful turquois food item. But this pond scum does not just look beautiful. It comes with some amazing health benefits too. Spirulina is