Simazine is the most popular form of treatment for algae control in dams.
From the au.news.yahoo.com
The weedkillers atrazine and simazine were introduced in 1958.
From the newscientist.com
Fenton points out that these findings may extend beyond atrazine alone, and may be relevant to other herbicides found in the same chlorotriazine family, including propazine and simazine.
From the sciencedaily.com
More examples
A herbicide used to control weeds (especially among crops)
Simazine is a herbicide of the triazine class. The compound is used to control broad-leaved weeds and annual grasses.
A chemical substance used in swimming pools and spas as an herbicide or algaecide. Mainly used for killing black algae.