Abstract: A two-piece filtering device for wastewater filtering systems is disclosed wherein the two-piece system is inserted into a tubular casing. The two-piece filtering system is comprised of an outer sleeve filter and an inner primary filter, the primary filter extending downwardly through an opening in the bottom portion of the sleeve filter and also having an opening formed in its end. After insertion into the tubular casing, the two-piece filtering system of the present invention forces effluent or other fluid to be treated upward through the interior of the primary filter, through slots formed in and subsequently through the sidewall of the sleeve filter. Thus, only treated effluent flows outward through the tubular casing outlet opening. The slots may be formed in both the sidewall of the primary filter and the sleeve filter. A seal may be provided between sidewall lower portion of the primary filter and may extend to the internal sidewall of the tubular casing to prevent untreated effluent therebetween.