Apparatus (10) for separating entrained solids from a fluid flow (e.g., pond water), comprises an inner chamber (12) and an outer chamber (14) thus enabling two different separation operations to be performed. Specifically, the outer chamber (14) is used for cyclonic separation, with fluid flowing into the chamber from inlet (16) being swirled into a vortex to effect separation of relatively coarse solid particles from the fluid flow. Once subjected to cyclonic separation, fluid overflows weirs (18) into the inner chamber (12) for removal of relatively fine particles and other contaminants by filtration using resilient foam (40), before flowing through outlet (22).