Nutrients - The major nutrients required for the growth of algae include carbon, hydrogen, nitrogen, oxygen and phosphorus.
Of these nitrogen and phosphorus are the ones which occur in very low concentration in water in relation to algal nutrients.
Thus they act as limiting factors for algal productivity.
Nitrogen is available in the form of ammonium or nitrate and phosphorus is available in the form of phosphates.
The increased concentrations of nitrogen and phosphorus in eutrophic waters are responsible for the excessive algal growth.
