Benzalkonium Chloride is a kind of cationic surfactant, belonging to nonoxidizing boicide. It can efficiently withhold algae propagation and sludge reproduction. Benzalkonium Chloride also has dispersing and penetrating properties, can penetrate and remove sludge and algae, has advantages of low toxicity, no toxicity accumulation, soluble in water, convenient in use, unaffected by water hardness.