Agri Kultuur January / January 2018 | Page 19

Construct the radial filter A clarifier or radial filter is a dedicated vessel that uses the properties of water to separate particles. Generally, water that is moving slower is unable to carry as many particles as water that is flowing faster. Therefore, the clarifier is constructed in such a way to speed up and slow down the water so that the particles concentrate on the bottom can be removed. In a radial filter, the water from the fish tank enters near the lower middle of the clarifier through a pipe. This pipe is positioned tangentially to the container thereby forcing the water to swirl in a circular motion inside AgriKultuur |AgriCulture the container. The centripetal force created by the circular motion of the water forces the solid waste in the water to the centre and bottom of the container, because the water in the centre of the vortex is slower than that on the outside. Once this waste is collected on the bottom, a pipe attached to the bottom of the container can be periodically opened, allowing the solid waste to flush out of the container. The clarified water exits the filter at the top, filtering through a secondary mesh filter, and flows from the outer container into the biofilter. The solid wastes trapped and removed contain nutrients and are very useful for the system or for garden plants in general. 19