One or more dilution tubes for increasing the dilution of pulp as it enters a thickener are provided. One or more pipes, referred to here as dilution tubes, can be added to sides of a feed pipe of a thickener. One end of a dilution tube can open to a tank of the thickener, and the other end can open into the feed pipe. As pulp flows through the feed pipe, low pressure suction can be created that pulls water from the tank, through the dilution tube, and into the feed pipe. The water pulled in through the dilution tube can increase the dilution of the pulp. A highly diluted pulp can contact a flocculent efficiently and lead to a high settling rate in a thickener. Accordingly, the use of dilution tubes can increase the efficiency of a thickener.