The only consumables that is not digested and is immediately absorbed, would be water, it is nothing but a polar compound that does not yield as much energy as all of the other molecules.
Increasing its pH because then the enzyme wont be ablr to work properly
One reason is because of its given color. Typically, Algae or moss grows in saturated areas. The reason it is been is because doc its pigment, or chlorophyll found in its anatomy.