Removeable Cage

A cage configured to retain plant based absorbent filtration media in a body of water, wherein the water has a direction of flow, wherein the cage is cuboid in shape having six rectangular faces and further comprises a lifting point and a pivot mechanism, wherein the faces comprise; a pair of opposed side walls, a pair of opposed end walls, a lower plate affixed to both the side walls and the end walls, and a releasably openable upper plate, wherein one of the pairs of opposed faces are permeable, and wherein the cage is configured to be oriented in the body of water with the direction of flow normal to the permeable faces, wherein the pivot mechanism is affixed to the opposed side walls, wherein the upper plate is hingably connected to either a side wall or an end wall, and wherein the upper plate comprises a locking mechanism to retain the upper plate in a closed configuration, so that the cage can be rotated until the upper plate is facing substantially downwards, and the upper plate can then be allowed to swing into an open configuration upon release of the locking mechanism. --- -- --- -- - - -- 17l