The present invention provides a method and apparatus for economical and efficient composting. The apparatus includes a manifold with lances coupled thereto for even fluid distribution throughout the compost. The manifold is designed to direct fluid flow to a portion of the lances while simultaneously removing fluid flow from the other portion of lances. This creates substantially uniform patterns of fluid injection and evacuation for uniform composting, reduced energy requirements and greater control of process conditions. Further, reversal of the fluid flow enhances control of process conditions and adds an automatic self cleaning aspect to the apparatus.