A filtration operator for filtering raw water, comprising a plurality of filtration units, a raw water reservoir, a conduit for conveying raw water from the raw water reservoir to individual ones of the filtration units, filter medium provided in each of the filtration units for filtering raw water, a respective raw water chamber configured to be in water communication with the raw water reservoir, the filtration units, and a pump chamber, a sludge filtering and recycling chamber for receiving sludge from the filtration units during a backwash cycle, and at least one positively charged bar disposed in each of the raw water chambers, as well as in a sludge receiving chamber associated with the sludge filtering and recycling chamber.