Algae are naturally occurring organisms in mostly in slow moving waters, that grow rapidly in waters with excess nutrients and warm temperatures.

Traditional water treatment methods, such as flocculation and chlorination do not remove cyanotoxins (hepatotoxin and neurotoxin) produced by the harmful algal blooms of the blue-green cyanobacteria algae.

PAC (powdered activated carbon) and GAC (granular active carbon) filters are both very effective (depending on the toxin concentrations and water properties) in absorbing algal micropollutants and by that means to protect against the intrusion of algal toxins into the drinking water system.