Abstract: An anti-scaling device comprises a hollow central body for mounting on a bar and several spike units extending outwardly from the body in different directions. Pairs of spike units are rotatably and preferably detachably mounted on opposite sides of the central body. The device may further comprise serrated webs extending outwardly from the central body between the spike units. The device may also comprise rows of sharp-edged teeth axially aligned along the central body. Alternatively, the spike units may be partially rotatable serrated propellers or may be pivotably rotatably mounted. The device may be moulded from plastic material.