The Spherical shape and multitude of recessed cavities which each have their own air ports produce an ideal shape to grow and feed micro biological biota. The Bio Ball is made from a plastic which has a specific gravity of approx .98. Allowing the sphere to float freely, and making allowance for the extra weight of the growing biota to ensure that the balls will cycle down to the bottom of the aeration chamber. They then rise through the column of air bubbles to the surface again thus constantly traveling through both the food source and the oxygen stream.
The spherical shape provides a snag free surface whilst the deep cavities protect the growing organisms from concussive blows whilst moving through the chamber.