What is a Vertical Flow Reed-bed?

A vertical flow reed-bed is a reed-bed in which the effluent is periodically dosed uniformly over the surface of the bed by means of a network of pipes.  The effluent percolates vertically down through the media and is collected by drainage pipes at the bottom which discharge to the next reed-bed in a series or directly into a watercourse or pond.  The bed then remains empty of water until the next dose is applied.

The matrix of the bed is made up of layers of sand and gravel.

Vertical Flow Reed-beds are designed to be aerobic and to nitrify ammonia converting it into nitrates and nitrites.