AFM Grade 2, Activated Filter Media, 25 kg
The coarse layer under grade 1. Or the whole bed at high flow.
Activated filter media grade 2, 1 to 2 mm, 25 kg. One bag goes in the bottom of every AFM vessel as the support layer around the strainer, spreading the backwash and keeping the fine grade 1 above it. On its own it is the single-grade choice for coarse sediment at higher flows, ahead of a finer stage.
Vessel, valve and media together: the complete kitsWhy glass beats sand
Sand filters grow biofilm. Within months the grains are coated, the bed channels, and bacteria colonise the filter that was meant to remove them. Activated filter media is made from recycled glass with a surface that resists biofilm and carries a slight charge, so it filters finer than sand (about 4 micron without a coagulant), never needs replacing, and backwashes with a third less water because it is lighter and rinses clean.
How much to buy
| Vessel | Grade 2 as support | Grade 2 alone |
|---|---|---|
| 45 L vessel | 1 bag | 2 bags |
| 75 L vessel (ours) | 1 bag | 3 bags |
| 100 L vessel | 1 bag | 4 bags |
Backwashing
With the grade 1 above it, weekly at 40 metres an hour for 12 to 15 minutes. The coarser grains stay at the bottom through every backwash, which is the point of them.
Before you buy.
Goes with it.
Whole shopAFM Grade 1, Activated Filter Media, 25 kg
Glass that filters finer than sand and never needs replacing.
Riser and distributors included75 Litre FRP Vessel with Riser and Distributors
The tank a filter or softener is built in. With the parts everyone else sells separately.
Free courierRunxin F67C1 Automatic Filter Valve
Backwashes itself. Set the days, set the hour, forget it.