Abstract The subject of invention is a method of a mass culture of rotifer Lecane, potentially used in activated sludge bulking control in wastewater treatment plants, applied out of the activated sludge bioreactors, characterized by maintaining culture in plates (1), in a liquid medium and fed with artificial nourishment. Plates (1) are composed in vertical modules, preferentially 10 plates each, one flat-bottom base (3) and cover (4) per module. Plates (1) have ribbed bottom (2) with vents (5) protected by vertical tubes (6) enabling air circulation and preventing mixis between plates (1).
