A method for treating drilling mud includes directing a first flow portion of a flow of drilling mud to a decanter centrifuge, directing a second flow portion of the flow of drilling mud to a solids particle recovery hopper, and separating an underflow from the first flow portion with the decanter centrifuge, wherein the underflow includes first solids particles having a first density. The underflow is directed to the solids particle recovery hopper, the underflow is mixed with the second flow portion in the solids particle recovery hopper, and a flow of the mixed underflow and second flow portion is directed from the solids particle recovery hopper to an active mud tank.