Sediment Filter Kit, 75 L

Sand, silt, rust and cloudiness come out here, ahead of everything else. AFM is activated recycled glass: it filters finer than sand, its surface resists the biofilm that turns a sand bed into a colony, and it backwashes with a third less water. On a borehole, a river or a rain tank this is the stage that protects the carbon, the softener, the cartridges and the UV that follow.

1. Stand the vessel, fit the bottom strainer to the riser and drop the riser in, capped so no media enters it.
2. Pour in the grade 2 bag, then the two grade 1 bags. Fill with water and let the bed settle overnight.
3. Clip the top distributor to the valve, screw the valve on, connect inlet, outlet and drain.
4. Backwash for fifteen minutes until the drain runs clear, rinse, then service.

Backwash weekly, or when the pressure across the vessel rises 0.5 bar: about 50 litres a minute to the drain for twelve to fifteen minutes. The media does not wear; the only reason to take it out is to move the vessel.