Cationic polymers (e.g. polyacrylamide) having a high molecular weight require a much lower dose than inorganic metal salts (e.g. AlCl 3 , FeCl 3 , or Al 2 (SO 4 ) 3 ) to produce dense compact flocs with good settling characteristics. This study investigated the effect of a continuous low dosing of cationic polyacrylamide (PAM) to achieve efficient algal removal from a 1‐ha High Rate Algal Pond (HRAP) treating domestic wastewa...