Connect pipes to an already existing graywater bed. If you don't have a graywater bed, connect pipes to your toilets and run the pipes outside. According to Earthship Systems and Components, it is recommended to plant a blackwater reed bed at least 12 feet away from your main building.
Build a staggered reed bed using wooden panels. Lay the wooden panels into a rectangular box and then build up. Any size of wooden panels can be used but each bed should be at least one foot deep and three feet by two feet. Line the base of the container with PVC to ensure the waste material does not seep out into the ground.
Stagger four or more of these containers for the reed beds in a stepped pattern. Cut out sections in the wood at the base to allow water to flow into the next reed bed. Cut a section out of the last so that the clean water can run into the garden.
Fill each container a third full with gravel and stones. Then pour in soil to the top of the container. Plant your reeds and plants into the reed bed. If you are going to use the septic system at once, it is best to plant fully grown plants.