Effective mechanical filtration via seven layers of filter foam: - 4 x fine (yellow) - 3 x coarse (blue) One touch AUTO clean system While pump is running simply twist blue cleaning dial to ‘clean’ setting Motorised cleaning arm agitates foam surfaces dislodging dirt particles. Dirty water runs off to drain via dedicated waste outlet. Two cartridges of 45mm diameter biosphere bio media begin biological breakdown process. Hand-crafted extra large fibreglass chamber containing X1 bio media acts as a ‘floating bed’ encouraging healthy bacterial growth. 35 Litres of X1 media included. Max. recommended chamber capacity of X1 bio media is 60 litres. NOTE: UVC bulb included.