The two main components of plant fertilizers which affect algal growth when they are delivered to aquatic systems via runoff are nitrate and .

Nitrogen and phosphorous are the most prevalent aquatic pollution and contribute heavily to the excessive growth of algae in aquatic environments called algae blooms. The nitrogen from the fertilizers is found in molecules called nitrates which are compounds of both oxygen and nitrogen. Phosphorous helps algae to absorb carbon dioxide. So when the phosphorous levels are high the algae absorbs more carbon dioxide, which allows for faster photosynthesis and faster glucose production which leads to faster growth. Although algae need both nitrogen and phosphorous to grow, when the levels are too high the algae grows faster than the ecosystem can sustain leading to oxygen deprivation for the other aquatic organisms.